Metathesis of acetylenes

Abstract

Described are novel bimetallic complexes particularly useful as homogeneous catalysts for the metathesis of alkynes and metathesizable functionally substituted alkynes, and methods for the preparation of such complexes. The complexes are formed from (i) a Group VI-B metal compound having (a) quadruple metal to metal bonds between a pair of Group VI-B metal atoms at least one of which has an atomic number above 24, and (b) four monovalent anions with a k.sub.A greater than 10.sup.-14, and (ii) a Group III-A phenoxide, a Group III-A alkoxide or a Group IV-B metal alkoxide. Displacement of two of the anions appears to occur during formation of the complex. Usually the complexes can be produced very easily and quickly. All that is required is to establish intimate contact between components (i) and (ii), preferably in an innocuous liquid organic solvent. Addition of a small amount of a nitrile gives a faster and cleaner reaction. In some cases use of slightly elevated temperatures is desirable. A variety of acetylenic compounds were metathesized by use of a variety of these complexes as catalysts. In the course of the work, the following complexes were prepared, isolated, and characterized:Mo.sub.2 (OAc).sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2Mo.sub.2 (O.sub.2 CCMe.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2Mo.sub.2 (O.sub.2 CCF.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2[Mo.sub.2 (CD.sub.3 CN).sub.4 (OAc).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2.[Mo.sub.2 (THF).sub.4 (OAc).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2Mo.sub.2 (OAc).sub.2 [Al(p-OC.sub.6 H.sub.4 CH.sub.3).sub.4 ].sub.2Mo.sub.2 (OAc).sub.2 [Al(p-OC.sub.6 H.sub.4 CMe.sub.3).sub.4 ].sub.2

Description

TECHNICAL FIELD

This invention relates to metathesis of acetylenes, to novel bimetallic complexes especially useful as homogeneous catalysts for such metathesis, and to the synthesis of the complexes.

BACKGROUND

Prior work on homogeneous catalysts for the metathesis of acetylenes is relatively sparse. The first published report on this subject appears to be that of Mortreaux, et al., J. Mol. Catal., 1977, 2, 73. Their work involved use of Mo(CO).sub.6. Devarajan, et al. improved upon and studied this system in some detail. See J. Organomet. Chem., 1979, 181, 99. Most of the more recent work in the field is that of R. R. Schrock and his colleagues at the Massachusetts Institute of Technology who have studied certain compounds or complexes of molybdenum and tungsten.

See for example:

Clark et al., J. Am. Chem. Soc. 1978, 100, 6774 Wengrovius et al., J. Am. Chem. Soc. 1981, 103, 3932 Sancho et al., J. Mol. Catal. 1982, 15, 75 Schrock et al., Organometallics 1982, 1, 1645 McCullough et al., J. Am. Chem. Soc. 1984, 106, 4067 Schrock, U.S. Pat. No. 4,427,595 (1984) In addition, a catalyst based on MoO.sub.2 (acac).sub.2 has been reported by Bencheick et al., J. Mol. Catal. 1982, 15, 93.

It appears that all of the homogeneous catalysts studied to date have involved compounds having a single atom of Mo or W.

Lamotte et al., Cryst. Struct. Comm., 1981, 10, 59, report the structure of a bimetallic complex of dimolybdenum tetraacetate and aluminum triisopropoxide. However no utility of any kind is suggested for the complex.

THE INVENTION

A new type of catalysts for catalytically metathesizing a metathesizable acetylene compound has now been discovered. The catalysts used pursuant to this invention consist essentially of a complex formed from (i) a Group VI-B metal compound having (a) quadruple metal to metal bonds between a pair of Group VI-B metal atoms at least one of which has an atomic number above 24, and (b) four monovalent anions with a k.sub.A greater than 10.sup.-14, and (ii) a Group III-A or IV-B metal alkoxide or phenoxide. Preferably both of the Group VI-B metal atoms have an atomic number above 24, and it is likewise preferred that the k.sub.A of the four monovalent anions be greater than 10.sup.-12. Among the advantages of this invention is that some of the compounds of (i) and many of the compounds of (ii) are available as articles of commerce.

In another of its embodiments this invention provides a new class of catalysts or complex compounds which are particularly effective in the metathesis of metathesizable alkynes. They are compositions or complexes formed from (i) a Group VI-B metal compound having (a) quadruple metal to metal bonds between a pair of Group VI-B metal atoms of atomic number above 24, and (b) four monovalent anions with a k.sub.A greater than 10.sup.-14 (and preferably greater than 10.sup.-12), and (ii) a Group III-A metal phenoxide, particularly aluminum phenoxides. Such complexes have in general the highest activity in the metathesis of metathesizable acetylenes.

The metathesis catalysts used pursuant to this invention usually can be produced very easily and quickly. All that is required is to establish intimate contact between components (i) and (ii). In some cases use of slightly elevated temperatures is desirable. While this reaction may be performed in bulk (no added solvent) it is preferable to synthesize the compounds of this invention in an innocuous liquid organic solvent. Suitable solvents for synthesis (and for metathesis as well) include aromatic, aliphatic and cycloaliphatic hydrocarbons, fluorocarbons, halogenated aromatic hydrocarbons, relatively unreactive halogenated aliphatic hydrocarbons (e.g., methylene dichloride, ethylene dichloride, etc.), ethers, and the like. Acetonitrile, while useful as a reaction solvent in the synthesis of the catalysts, destroys metathesis activity if used as the solvent for the metathesis reaction. Thus in selecting a solvent for the metathesis reaction it is suggested that hydroxylic and dipolar aprotic solvents may be inappropriate choices as they may impair or destroy catalytic activity. In any given case the suitability of a proposed solvent for the production of the complexes and/or for the metathesis reaction may be readily determined by the expedient of performing a few simple tests utilizing the procedures described in the ensuing examples.

As is well known a variety of acetylenic compounds are metathesizable, including unsymmetrical dialkylacetylenes such as 3-heptyne, 3-octyne, 3-nonyne, 4-nonyne and their higher homologs containing up to about 36 or more carbon atoms; arylacetylenes, such as 1-phenyl-1-butyne, 1-phenyl-2-butyne, 1-(p-tolyl)-2-penatyne, and their higher homologs containing up to about 40 or more carbon atoms, and the like. It is also well known that mixtures of suitable metathesizable acetylenic compounds may be co-metathesized to produce a product differing from either reactant. A few illustrative mixtures suitable for co-metathesis include 3-hexyne and 4-octyne, 3-heptyne and 5-decyne, and 1,4-diphenyl-2-butyne and 3-hexyne. Compounds with a single phenyl or a methyl group directly attached to a carbon atom carrying the acetylene triple bond show reduced activity to the catalysts of this invention. Thus preferred acetylenic compounds for use in the methathesis process (including co-metathesis) are those having the general formula:

R.sup.1 --CH.sub.2 --C C--CH.sub.2 --R.sup.2 where R.sup.1 and R.sup.2 are similar or dissimilar organic groups, such as alkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, alkenyl, cycloalkenyl, alkylthio, cycloalkylthio, cycloalkylalkylthio, arylthio, aralkylthio, alkenylthio, cycloalkenylthio, alkoxy, cycloalkoxy, cycloalkylalkoxy, aryloxy, aralkoxy, alkenoxy, cycloalkenoxy, anilino and ring-substituted anilino, haloalkyl, halocycloalkyl, halocycloalkylalkyl, haloaryl, haloaralkyl, haloalkenyl, halocycloalkenyl, haloalkylthio, halocycloalkylthio, halocycloalkylalkylthio, haloarylthio, haloaralkylthio, haloalkenylthio, halocycloalkenylthio, haloalkoxy, halocycloalkoxy, halocycloalkylalkoxy, haloaryloxy, haloaralkoxy, haloalkenoxy, halocycloalkenoxy, cyanoalkyl, cyanocycloalkyl, cyanocycloalkylalkyl, cyanoaryl, cyanoaralkyl, cyanoalkenyl, cyanocycloalkenyl, trihydrocarbylsiloxy, and other similar groups which do not prevent the metathesis reaction from taking place. Each of the organic groups, R.sup.1 and R.sup.2 preferably contains up to about 20 carbon atoms, and most preferably up to about 12 carbon atoms. Naturally when only one such acetylenic compound is being metathesized, R.sup.1 and R.sup.2 should differ from each other so that the metathesis product will differ from the initial acetylenic compound. In co-metathesis, R.sup.1 and R.sup.2 need only differ from compound to compound in the initial co-metathesis mixture, as for example in the case of a mixture of 3-hexyne and 4-octyne.

The complexes of this invention may be solvated with ethers, or other complexing solvents in which they are formed, or in which component (i) above is formed. Likewise, some of the complexes of this invention may be further complexed with organophosphine ligands, organoarsine ligands, organostibine ligands, or the like, such as the trihydrocarbylphosphines and the bis(dihydrocarbylphosphino)alkanes, and their corresponding arsenic and antimony derivatives.

Component (i) is composed of any salt containing in the molecule two atoms of a Group VI-B metal, at least one of which is molybdenum or tungsten (preferably both are molybdenum and/or tungsten), and the anions of which have a k.sub.A greater than 10.sup.-14 and preferably above 10.sup.-12. Thus, these salts are derivatives of relatively strong acids such as HCl, HNO.sub.3, carboxylic acids, and the like. Numerous illustrative examples of such salts and their complexes are given in the ensuing experimental section.

Component (ii) also comprises a wide variety of materials, such as the phenoxides and alkoxides (including cycloalkoxides) of the Group III-A elements (B, Al, Ga, In, Tl) and the alkoxides (including cycloalkoxides, etc.) of the Group IV-B metals (Ti, Zr, Hf). The III-A phenoxides and alkoxides are preferably triphenoxides or trialkoxides (M(OR).sub.3), but may be a diphenoxy, dialkoxy, monophenoxy or monoalkoxy derivative (R'M(OR).sub.2 ; R.sub.2 MOR) where R' is a hydrocarbyl group, preferably alkyl or the like and R is a phenoxy or alkoxy group, i.e., phenoxy or substituted phenoxy, or alkoxy or substituted alkoxy). A broad range of substituents can be present on the phenoxy group(s) including hydrocarbon groups, halogen substituents, alkoxy and aryloxy groups, and many others. The IV-B alkoxides are most commonly the tetraalkoxides, although here again one or more of such alkoxy groups may be replaced by a suitable substituent, such as halogen, hydrocarbyl, aryloxy, and the like. Group IV-B phenoxides also form complexes pursuant to this invention although they appear to have little activity as metathesis catalysts for acetylenic compounds. Usually each phenoxy or alkoxy group in component (ii) will contain no more than about 18 carbon atoms, although this is not deemed to constitute a critical limitation as there is no apparent reason why compounds with even larger phenoxy and alkoxy groups may not be used. The same considerations apply to the other organic groups that are optionally present in the phenoxides or alkoxides--these also will usually contain no more than about 18 carbon atoms each, although here again this should not be construed as constituting a critical limitation. Rather this speaks to what is commonly available from the usual commercial sources, and thus goes to matters of convenience and ready availability. Irrespective of its makeup, the important consideration is that component (ii) should be capable of complexing with the Group VI-B compound employed as component (i).

It appears on the basis of the available experimental evidence that components (i) and (ii) when brought together under suitable reaction conditions undergo a displacement reaction in which two of the anions of component (i) are replaced by pair of anionic ligands derived from the Group III-A or IV-A alkoxide or phenoxide employed as component (ii). For example, careful study of the reaction between Mo.sub.2 (O.sub.2 CR).sub.4 (R=methyl, tertiary butyl, trifluoromethyl) and Al(OC.sub.6 H.sub.4 Cl).sub.3 has resulted in isolation of air sensitive orange crystals of the composition [Mo.sub.2 (O.sub.2 CR).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 as judged from nmr spectra. Isolated yields of these novel complexes of this invention were 60% (R=methyl), 40% (R=tertiary butyl), and 20% (R=trifluoromethyl).

When forming the isolated complexes where R=methyl or tertiary butyl, it was discovered that faster and cleaner reactions occurred when a small amount of acetonitrile was added to the reaction mixture. The role played by the nitrile in enhancing such reactions is unknown.

Accordingly, this invention provides in another of its embodiments the process of producing a complex of (i) a Group VI-B metal compound having (a) quadruple metal to metal bonds between a pair of Group VI-B metal atoms one and preferably both of which have an atomic number above 24, and (b) four monovalent anions with a k.sub.A greater than 10.sup.-14 and preferably above 10.sup.-12, and (ii) a Group III-A phenoxide or IV-B alkoxide which comprises effecting reaction between components (i) and (ii). Preferably the reaction is conducted in the presence of a nitrile, such as acetonitrile, propionitrile, benzonitrile, and the like. Although nitriles tend to inhibit or destroy the catalytic activity of the catalysts of this invention when used as solvents for metathesizing acetylenic compounds, the amount of nitrile which remains complexed with the catalysts of this invention during their synthesis does not appear to interfere with their ability to function in the metathesis reaction.

A number of complexes were prepared in appropriate solvents and used as catalysts for metathesis of various acetylenic hydrocarbons, mainly 3-heptyne. All manipulations were performed under nitrogen or argon by using either Schlenk or dry nitrogen box techniques. Tetrahydrofuran (THF) was dried, distilled from sodium/benzophenone, and stored under nitrogen over 4 angstrom molecular sieves. Other solvents were passed through an alumina column, dried over 4 angstrom molecular sieves, deoxygenated with argon, and stored in the dry box. Acetylenes were obtained from standard sources and were passed through an alumina column, dried over 4 angstrom molecular sieves, and stored in the dry box. Hydrogen, obtained from Mathieson, was used as received. Alkylaluminum compounds were commercial products of Ethyl Corporation and were used as received. Dimolybdenum tetraacetate (Mo.sub.2 (OAc).sub.4) and dichrominum tetraacetate (Cr.sub.2 (OAc).sub.4 2H.sub.2 O) were obtained from Aldrich Chemical Company. Prepared by literature methods were the following:

Mo.sub.2 (O.sub.2 CCF.sub.3).sub.4 (Cotton, F. A.; Norman, J. G. J. Coord. Chem. 1971, 1, 161); Mo.sub.2 (OPv).sub.4 (i.e., dimolybdenum tetrapivalate) (McCarley, T. E.; Templeton, J. L.; Colburn, T. J.; Katovic, V.; Hoxmeier, R. J. Adv. Chem. Ser. 1976, 150, 318); Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2, Mo.sub.2 Cl.sub.2 (PPh.sub.3).sub.2 (OAc).sub.2, Mo.sub.2 Cl.sub.2 (PEt.sub.3).sub.2 (OAc).sub.2, Mo.sub.2 Cl.sub.4 (DPPM).sub.2 (DPPM=1,2-bis(diphenylphosphino)methane) and Mo.sub.2 Cl.sub.4 (PEt.sub.3).sub.4 (Green, M. L. H.; Parkin, G.; Bashkin, J.; Fail, J.; Prout, K. J. Chem. Soc. Dalton Trans. 1982, 2519); [Mo.sub.2 (CH.sub.3 CN).sub.4 (OAc).sub.2 ][CF.sub.3 SO.sub.3 ].sub.2 (Telser, J. Drago, R. S. J. Inorg. Chem. 1984, 23, 1798); MoW(OPv).sub.4 (molybdenum tungsten tetrapivalate) (Katovic, V.; Templeton, J. L.; Hoxmeier, R. J.; McCarley, R. E. J. Am. Chem. Soc. 1975, 97, 5300); WCl.sub.4 (Schrock, R. R.; Sturgeoff, L. G.; Sharp, P. R. Inorg. Chem. 1983, 22, 2801); W.sub.2 (O.sub.2 CCF.sub.3).sub.4 (Santure, D. J.; McLaughlin, K. W.; Huffman, J. C.; Sattelberger, A. P. Inorg. Chem. 1983, 22, 1877); and W.sub.2 (OPv).sub.4 (ditungsten tetrapivalate) (Santure, D. J.; Huffman, J. C.; Sattelberger, A. P. Inorg. Chem. 1985, 24, 371). Other reagents were obtained from standard sources and were opened and stored in the dry box.

NMR spectra (.sup.1 H, .sup.13 C, and .sup.19 F) were obtained on a Nicolet NC360NB spectrometer. Chemical shifts (.sup.1 H and .sup.13 C) are reported in ppm relative to the residual protons or carbons in the solvent. Coupling constants are reported in Hertz. Mass spectra were obtained on a Finnigan spectrometer. Gas chromotography was performed on a Varian 3700 gas chromatograph connected to a Hewlett-Packard 3390A integrator.

EXAMPLE 1

Preparation of Mo.sub.2 (OAc).sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2

Al(p-OC.sub.6 H.sub.4 Cl).sub.3 was prepared in situ by stirring 1.530 (11.90 mmol) of p-ClC.sub.6 H.sub.4 OH and 0.543 mL (3.96 mmol) of AlEt.sub.3 (added over a 10 minute period) in 20-mL of toluene for 3 hours. To the resulting white milky suspension was added 0.427 g (0.99 mmol) of Mo.sub.2 (OAc).sub.4 and 0.052 mL (1.0 mmol) of CH.sub.3 CN. After stirring for 48 hours at 30.degree. C., the reaction mixture was filtered through a pad of Celite to remove solids. The red-yellow filtrate was concentrated to a volume of about 2-3 mL under a stream of nitrogen and allowed to stand for 3 hours. The yellow-orange crystals of product were filtered, washed three times with 5 mL or petroleum ether (b.p. 35.degree.-60.degree. C.) and dried under a 15 psi stream of nitrogen to yield 0.753 g (55%) of Mo.sub.2 (OAc).sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2. .sup.1 H NMR(360 MHz, C.sub.6 D.sub.6) 2.38(S, 6H, O.sub.2 CCH.sub.3); 7.105(A.sub.2 B.sub.2 J=65.0, 10.8 Hz, 8H, OC.sub.6 H.sub.4 Cl); 6.67 (A.sub.2 B.sub.2 J=176.9, 10.8 Hz, 8H, OC.sub.6 H.sub.4 Cl); 6.525(A.sub.2 B.sub.2 J=43.3, 10.8 Hz, 16H, OC.sub.6 H.sub.4 Cl). .sup.13 C NMR (90.5 MHz, C.sub.6 D.sub.6): 22.87(O.sub.2 CCH.sub.3); 187.03(O.sub.2 CCH.sub.3); 156.28, 156.22, 151.72 (AlOCC.sub.2 H.sub.2 C.sub.2 H.sub.2 CCl); 121.69, 121.05, 120.71 (AlOCC.sub.2 H.sub.2 C.sub.2 H.sub.2 CCl); 130.35, 130.23, 129.75 (AlOCC.sub.2 H.sub.2 C.sub.2 H.sub.2 CCl); 130.55, 125.61, 124.99 (AlOCC.sub.2 H.sub.2 C.sub.2 H.sub.2 CCl).

EXAMPLE 2

Preparation of Mo.sub.2 (O.sub.2 CCMe.sub. 3).sub.2 [Al(p-OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2

Al(p-OC.sub.6 H.sub.6 Cl).sub.3 was prepared in situ by adding 0.163 mL (1.19 mmol) AlEt.sub.3 dropwise to 0.45 g (3.57 mmol) of p-ClC.sub.6 H.sub.4 OH in 8.0 mL of toluene and stirring for 3.0 hours. To the white suspension of Al(OC.sub.6 H.sub.4 Cl).sub.3 was added 0.177 g (0.297 mmol) of Mo.sub.2 (O.sub.2 CCMe.sub.3).sub.4 and 0.008 mL (0.153 mmol) of CH.sub.3 CN. After stirring the mixture at 30.degree. C. for 24-48 hours, a bright orange-red solution was obtained. The solution was filtered through a pad of Celite then evaporated to dryness. The dark orange/white residue was extracted 4 times with 5 mL portions of a toluene-petroleum ether (b.p. 35.degree.-60.degree. C.) (1:4 v/v mixture and the extract solutions were combined and filtered through a Celite pad. A dark orange oil was obtained by evaporation of the solvent from the filtrate. This oil was dissolved in a minimum amount of toluene and the solution was carefully layered with petroleum ether. Yellow-orange needles of the product were present after 16 hours. These were filtered, washed twice with 3 mL portions of petroleum ether and dried yielding 0.177 g (41%) of Mo.sub.2 (O.sub.2 CCMe.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2. .sup.1 H NMR (360 MHz, C.sub.6 D.sub.6) 1.42(S, 18H, O.sub.2 CCMe.sub.3); 6.625(A.sub.2 B.sub.2, J=187.8, 10.8 Hz, 8H, OC.sub.6 H.sub.4 Cl); 6.575(A.sub.2 B.sub.2, J=57.8, 10.8 Hz, 16H, OC.sub.6 H.sub.4 Cl); 6.975(A.sub.2 B.sub.2, J=137.2, 10.83 Hz, 8H, OC.sub.6 H.sub.4 Cl).

EXAMPLE 3

Preparation of Mo.sub.2 (O.sub.2 CCF.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2

Al(p-OC.sub.6 H.sub.4 Cl).sub.3 was prepared in situ by adding 0.101 mL (0.74 mmol), AlEt.sub.3 dropwise to 285 mg (2.22 mmol) p-ClC.sub.6 H.sub.4 OH in 6 mL of toluene and stirring for 3 hours. To the white suspension was added 119 mg (0.185 mmol) Mo.sub.2 (O.sub.2 CCF.sub.3).sub.4. The mixture was then heated at 80.degree. C. for 18 hours. The reaction mixture was dark orange in color and contained a white solid. The mixture was filtered through a pad of Celite to remove the solids and the filtrate was then evaporated to dryness leaving an orange brown residue. The residue was dissolved in a minimum amount of toluene and hexane was carefully layered over the solution. Orange crystals of product were present after 2 hours. These were filtered, washed twice with 2 mL portions of hexane, then dried to yield 55 mg (20%) of Mo.sub.2 (O.sub.2 CCF.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2..sup.1 H NMR (360MHz, C.sub.6 D.sub.6): 6.488 (A.sub.2 B.sub.2, J=97.5, 9.0 Hz, 16H, OC.sub.6 H.sub.4 Cl); 6.855 (A.sub.2 B.sub.2, J=149.9, 9.0 Hz, 16H, OC.sub.6 H.sub.4 Cl). .sup.19 F NMR (339 MHz, C.sub.6 D.sub.6, Cl.sub.3 CF external reference): 5.45 (S, O.sub.2 CCF.sub.3). The integral ratio between -O.sub.2 CCF.sub.3 and -OC.sub.6 H.sub.4 Cl was not obtained.

EXAMPLE 4

Reaction of Mo.sub.2 (OAc).sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 with CD.sub.3 CN

Mo.sub.2 (OAc).sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 (9 mg; 0.007 mmol) was dissolved in 0.8 mL of CD.sub.3 CN to give a bright purple solution. The solution was filtered into a NMR tube and the spectrum recorded at 360 MHz (22.degree. C.). An A.sub.2 B.sub.2 pattern was seen for the AlOC.sub.6 H.sub.4 Cl protons (6.895 J=104.7, 7.2 Hz, 32H) and a singlet was seen for the O.sub.2 CCH.sub.3 proton (2.90, 6H) which is consistent with the formation of:

[Mo.sub.2 (CD.sub.3 CN).sub.4 (OAc).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2.

EXAMPLE 5

Reaction of Mo.sub.2 (OAc).sub.2 [Al(p-OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 with THF

Mo.sub.2 (OAc).sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 (5 mg; 0.004 mmol) was dissolved in about 0.6 mL of C.sub.6 D.sub.6 then filtered into a NMR tube. To the orange solution was added 0.1 mL of THF. An immediate color change to red-purple was observed. The spectrum was recorded at 360 MHz (22.degree. C.). An A.sub.2 B.sub.2 pattern was seen for the AlOC.sub.6 H.sub.4 Cl protons (6.835, J=101.1, 10.4 Hz, 32H) and a singlet was seen for the O.sub.2 CCH.sub.3 protons (2.76, 6H) which is consistent with the formation of

[Mo.sub.2 (THF).sub.4 (OAc).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2.

EXAMPLE 6

Preparation of Mo.sub.2 (OAc).sub.2 [Al(p-OC.sub.6 H.sub.4 CH.sub.3).sub.4 ].sub.2

Al(p-OC.sub.6 H.sub.4 CH.sub.3).sub.3 was prepared in situ by adding 0.576 mL (4.21 mmol) AlEt.sub.3 dropwise to a solution of 1.37 g (12.63 mmol) p-CH.sub.3 C.sub.6 H.sub.4 OH in 20 mL of toluene and stirring for 3 hours. To the resulting white suspension was added 0.45 g (1.05 mmol) of Mo.sub.2 (OAc).sub.4 and 0.052 mL (1.0 mmol) of CH.sub.3 CN. After stirring for 7 days at 30.degree. C. the reaction mixture was filtered through a pad of Celite to remove solids. Solvent was removed the red-brown filtrate under a stream of nitrogen. The resulting dark red-brown oil was crystallized from a mixture of CH.sub.2 Cl.sub.2 and hexane. The sticky material was recrystallized from CH.sub.2 Cl.sub.2 /hexane to afford 0.58 g (46%) of dark yellow crystals of Mo.sub.2 (OAc).sub.2 [Al(p-OC.sub.6 H.sub.4 CH.sub.3).sub.4 ].sub.2. .sup.1 H NMR(360 MHz, C.sub. 6 D.sub.6); 2.92(S, 6H, O.sub.2 CCH.sub.3); 2.11(S, 12H, OC.sub.6 H.sub.4 CH.sub.3); 1.67(S, 12H, OC.sub.6 H.sub.4 CH.sub.3); 6.780(A.sub.2 B.sub.2 J=235, 7.2 Hz, 16H, OC.sub.6 H.sub.4 CH.sub.3); 6.985(A.sub.2 B.sub.2 J=25.3, 7.2 Hz, 16H, OC.sub.6 H.sub.4 CH.sub.3).

EXAMPLE 7

Preparation of Mo.sub.2 (OAc).sub.2 [Al(p-OC.sub.6 H.sub.4 CMe.sub.3).sub.4 ].sub.2

Aluminum tris(p-tert-butylphenoxide), Al(p-OC.sub.6 H.sub.4 CMe.sub.3).sub.3 was prepared in situ by adding 0.60 mL (4.4 mmol) of AlEt.sub.3 dropwise to a solution of 1.97 g (13.08 mmol) p-Me.sub.3 CC.sub.6 H.sub.4 OH in 25 mL of toluene and stirring overnight at 30.degree. C. To the resulting clear and colorless solution was added 0.468 g (1.09 mmol) of Mo.sub.2 (OAc).sub.4 and 0.052 mL (1.0 mmol) of CH.sub.3 CN. After stirring at 30.degree. C. for ca. 72 hours, the solution was red-yellow and contained a white precipitate. The solution was filtered through a pad of Celite to remove solids and then evaporated under a stream of nitrogen to a dark colored oil. The oil was extracted 3 times with 10 mL portions of pentane and the combined extract solutions were filtered through Celite. The filtrate was concentracted to precipitate a light yellow powder. The powder was filtered, washed with a minimum amount of pentane, and then dried under a stream of N.sub.2 to give 0.35 g (21%) of Mo.sub.2 (OAc).sub.2 [Al(p-OC.sub.6 H.sub.4 CMe.sub.3).sub.4 ].sub.2. .sup.1 H NMR(360 MHz, C.sub.6 D.sub.6) 1.00(S, 36H, OC.sub.6 H.sub.4 CMe.sub.3); 1.20(S, 18H, OC.sub.6 H.sub.4 CMe.sub.3); 1.25(S, 18H, OC.sub.6 H.sub.4 CMe.sub.3); 2.63(S, 6H, O.sub.2 CCH.sub.3); 6.92(A.sub.2 B.sub.2 J=141, 7.2 Hz, 16H, OC.sub.6 H.sub.4 CMe.sub.3); 6.93(A.sub.2 B.sub.2 J=90.3, 7.2 Hz 8H, OC.sub.6 H.sub.4 CMe.sub.3); 7.43(A.sub.2 B.sub.2 J=32, 7.2 Hz, 8H, OC.sub.6 H.sub.4 CMe.sub.3).

Metathesis reactions were performed using a variety of catalysts of this invention (preformed as in the above Examples or prepared in situ) and representative acetylenic hydrocarbons. These reactions were performed by first adding an appropriate quantity of a bimetal complex (either component (i) or a preformed complex of this invention) to a two dram vial equipped with a small stirring bar and then dissolving the complex in a suitable solvent. In those cases where, pursuant to this invention, component (ii) was being used to form the catalyst in situ. component (ii) was added at this point followed by addition of the desired acetylenic substrate. In experiments where either a Hpreformed bimetal complex of this invention or only a component (i) bimetal complex was used, the substrate was added directly to the solution of the particular bimetal complex. Reactions carried out at 32.degree. C. were performed in a dry box by simply stirring the solution. The reactions carried out at elevated temperatures were performed by removing the tightly capped reaction vial from the dry box and placing it in an aluminum block heater set at the desired temperature. Reactions were monitored and products were identified by GC or GC/MS.

The conditions and results of metathesis reactions of this invention using 3-heptyne are summarized in Table I. Table II gives the conditions and results of reactions involving metathesis of 2-heptyne with various catalysts of this invention. In Table III are shown the conditions and results of reactions in which 1-phenyl-1-butyne was metathesized with catalysts of this invention. The results in Table IV indicate that no metathesis occurs when using only a component (i) bimetal complex. In these tables the following additional abbreviations are used:

ACN=acetonitrile MDC=methylene dichloride Bz=benzene Tol=toluene BTN=butyronitrile ClBz=chlorobenzene Pent=pentane ns=no separate solvent added; reaction run neat na=no activity wa observed TABLE I__________________________________________________________________________3-Heptyne Metathesis Reactions2 EtC.tbd.CPr.fwdarw.EtC.tbd.CEt + PrC.tbd.CPrEx. Component (i) Component (ii) Alkyne PercentNo. (mmoles) (mmoles) mmoles Conditions Metathesis*__________________________________________________________________________ 8 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.028) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.012) THF/55.degree./6h 100 9 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.033) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.066) THF/55.degree./6h 10010 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.031) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.062) THF/32.degree./3h 8311 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.035) Et.sub.2 Al(OC.sub.6 H.sub.4 Cl) 1.070) THF/55.degree./3h 2012 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.035) EtAl(OC.sub.6 H.sub.4 Cl).sub.2 1.070) THF/55.degree./1h 7213 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.038) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.076) THF/55.degree./1h 10014 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.030) Al(OC.sub.6 H.sub.5).sub.3 (.030) 1.0 THF/55.degree./1h 5715 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.030) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.060) ACN/55.degree./2h na16 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.028) Al(OC.sub.6 H.sub.4 Cl).sub.3 2.856) THF/55.degree./20h 7917 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.033) Al(OC.sub.6 H.sub.4 Cl).sub.3 3.366) MDC/55.degree./19h 7718 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.031) Al(OC.sub.6 H.sub.4 F).sub.3 3.162) THF/55.degree./24h 6819 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.026) Al(OC.sub.6 H.sub.5).sub.3 (.055) 2.6 THF/55.degree./24h 3320 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.039) Al(OC.sub.6 H.sub.5).sub.3 (.102) 1.0 THF/55.degree./20h 9021 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.026) Ti(O-- .sub.-i-Pr).sub.4 (.052) 1.0 THF/55.degree./18h 4122 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.029) Ti(O-- .sub.-i-Pr).sub.4 (.060) 1.0 Bz/55.degree./18h na23 Mo.sub. 2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.021) Zr(O-- .sub.-i-Pr).sub.4 .sub.-i-PrOH 1.049) THF/55.degree./18h 724 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.039) Ti(O- -n-Bu).sub.4 (.08) 1.0 THF/55.degree./16h 1125 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.034) Al(O- -n-Bu).sub.4 (.083) 1.0 THF/55.degree./66h 6126 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.102) Ti(O--C.sub.6 H.sub.4 Cl).sub.4 2.037) THF/55.degree./18h na27 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.038) Ti(O--C.sub.6 H.sub.4 Cl).sub.4 1.034) THF/55.degree./18h trace28 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.025) Al(O- -t-bu).sub.3 (.19) 1.0 THF/55.degree./16h 1329 Mo.sub.2 Cl.sub.2 (PPh.sub.3).sub.2 (OAc).sub.2 (.016) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.064) THF/55.degree./16h 10030 Mo.sub.2 Cl.sub.2 (PPh.sub.3).sub.2 (OAc).sub.2 (.018) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.036) THF/55.degree./1h 4731 Mo.sub. 2 Cl.sub.2 (PPh.sub.3).sub.2 (OAc).sub.2 (.020) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.040) ACN/55.degree./1h na32 Mo.sub.2 Cl.sub.2 (PEt.sub.3).sub.2 (OAc).sub.2 (.04) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.08) THF/55.degree./72h 10033 Mo.sub.2 Cl.sub.4 (DPPM).sub.2 (.021) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.042) THF/55.degree./72h 10034 Mo.sub.2 Cl.sub.4 (DPPM).sub.2 (.017) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.034) THF/55.degree./18h 3735 Mo.sub.2 Cl.sub.4 (PEt.sub.3).sub.4 (.023) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.046) THF/55.degree./72h 936 [Mo.sub.2 (CH.sub.3 CN).sub.4 (OAc).sub.2 ][CF.sub.3 SO.sub.3 ].sub.2 (.021) Al(OC.sub.6 H.sub.4 Cl).sub.3 2.142) THF/55.degree./19h 8137 [Mo.sub.2 (CH.sub.3 CN).sub.4 (OAc).sub.2 ][CF.sub.3 SO.sub.3 ].sub.2 (.027) Al(OC.sub.6 H.sub.4 Cl).sub.3 2.762) THF/55.degree./18h 10038 [Mo.sub.2 (CH.sub.3 CN).sub.4 (OAc).sub.2 ][CF.sub.3 SO.sub.3 ].sub. 2 (.023) Ti(O- -i-Pr).sub.4 (.046) 1.5 THF/32.degree./18h 3539 Mo.sub.2 (OAc).sub.4 (.037) Al(OC.sub.6 H.sub.5).sub.3 (.144) 3.7 THF/55.degree./24h 3540 Mo.sub.2 (OAc).sub.4 (.037) Al(OC.sub.6 H.sub.4 F).sub.3 3.750) THF/55.degree./24h 8141 Mo.sub.2 (OAc).sub.4 (.046) Al(OC.sub.6 H.sub.4 Cl).sub.3 4.684) THF/55.degree./5h 8842 Mo.sub.2 (OAc).sub.4 (.047) Al(OC.sub.6 H.sub.4 Br).sub.3 4.788) THF/55.degree./3h 8143 Mo.sub.2 (OAc).sub.4 (.036) Al(OC.sub.6 H.sub.4 Cl).sub.3 3.644) Tol/55.degree./24h 7744 Mo.sub.2 (O.sub.2 CCF.sub.3).sub.4 (.064) Al(OC.sub.6 H.sub.4 F).sub.3 6.456) THF/55.degree./18h 1145 Mo.sub.2 (O.sub.2 CCF.sub.3).sub.4 (.039) Al(OC.sub.6 H.sub.4 Cl).sub.3 3.958) Tol/55.degree./24h 7846 Mo.sub.2 (O.sub.2 CCF.sub.3).sub.4 (.033) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.032) THF/32.degree./48h 747 Mo.sub.2 (OPv).sub.4 (.029) Al(OC.sub.6 H.sub.4 Cl).sub.3 2.916) THF/55.degree./18h 7948 MoW(OPv).sub.4 (.029) Al(OC.sub.6 H.sub.4 Cl).sub.3 2.916) THF/55.degree./18h 3049 MoW(OPv).sub.4 (.016) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.064) THF-BTN/55.degree./18h 8950 W.sub.2 (O.sub.2 CCF.sub.3).sub.4 (.029) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.064) THF/32.degree./66h 10051 W.sub.2 (O.sub.2 CCF.sub.3).sub.4 (.033) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.032) THF/32.degree./48h 6452 W.sub.2 (O.sub.2 CCF.sub.3).sub.4 (.023) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.092) THF-BTN/32.degree./16h 3853 W.sub.2 (OPv).sub.4 (.054) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.53) THF/32.degree./2h 5054 W.sub.2 (OPv).sub.4 (.054) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.53) THF/32.degree./18h 10055 W.sub.2 (OPv).sub.4 (.056) Al(OC.sub.6 H.sub.4 Cl).sub.3 1.533) ClBz/32.degree./18h trace56 W.sub.2 (OPv).sub.4 (.026) Al(O- -i-Pr).sub.3 (.104) 1.53 THF/32.degree./18h na57 W.sub.2 (OPv).sub.4 (.038) Ti(O- -i-Pr).sub.4 (.150) 2.33 THF/32.degree./72h na58 [Mo.sub.2 (OAc).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 1.56 .times. 10 - 2 M) -- 1.56 ClBz/55.degree./5h 7159 [Mo.sub.2 (OAc).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 --022) 2.0 THF/55.degree./3h 2160 [Mo.sub.2 (OAc).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 --025) 2.0 Tol/55.degree./2h 1761 [Mo.sub.2 (OAc).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 PPh.sub.3 (.092) 1.53 ClBz/70.degree./2h 6062 [Mo.sub.2 (OPv).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 --014) 1.0 ClBz/55.degree./6h 5163 [Mo.sub.2 (OCCF.sub.3).sub.2 ][Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 (.007) -- 1.53 THF/60.degree./5h 2464 [Mo.sub.2 (OAc).sub.2)][Al(p-OC.sub.6 H.sub.4 CH.sub.3).sub.4 ].sub.2 (.025) -- 1.0 THF/70.degree./18h 8165 [Mo.sub.2 (OAc).sub.2)][Al(p-OC.sub.6 H.sub.4 CMe.sub. 3).sub.4 ].sub.2 (.016) -- 1.0 Pent/32.degree./18h 5866 [Mo.sub.2 (OAc).sub.2)][Al(p-OC.sub.6 H.sub.4 CMe.sub.3).sub.4 ].sub.2 (.017) -- 7.6 ns/70.degree./18h 14__________________________________________________________________________ *Percent Metathesis = sum of 3hexyne & 4octyne divided by 3heptyne multiplied by 100 (data obtained from vpc area %) TABLE II__________________________________________________________________________2-Heptyne Metathesis Reactions2 MeC.tbd.CBu.fwdarw.MeC.tbd.CMe + BuC.tbd.CBuEx. Component (i) Component (ii) Alkyne PercentNo. (mmoles) (mmoles) mmoles Conditions Metathesis__________________________________________________________________________67 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.019) Al(OC.sub.6 H.sub.4 Cl).sub.3 (.038) 1.9 THF/55.degree./18h 1068 Mo.sub.2 (OAc).sub.4 (.047) Al(OC.sub.6 H.sub.4 Cl).sub.3 (.188) 4.7 THF/55.degree./20h 10069 [Mo.sub.2 (CH.sub.3 CN).sub.4 (OAc).sub.2 ][CF.sub.3 SO.sub.3 ].sub.2 (.019) Ti(O-- -i-Pr).sub.4 (.077) 1.5 THF/60.degree./18h 1770 [Mo.sub.2 (OAc).sub.4 ].sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 (.053) -- 4.0 THF/55.degree./5h ca2071 [W.sub.2 (O.sub.2 CCF.sub.3).sub.4 ] (.018) Al(OC.sub.6 H.sub.4 Cl).sub.3 (.073) 1.0 THF/32.degree./48h ca20__________________________________________________________________________ TABLE III__________________________________________________________________________1-Phenyl-1-Butyne Metathesis Reactions2 PhC.tbd.CEt PhC.tbd.CPh + EtC.tbd.CEtEx. Component (i) Component (ii) Alkyne PercentNo. (mmoles) (mmoles) mmoles Conditions Metathesis__________________________________________________________________________72 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.046) Al(OC.sub.6 H.sub.4 Cl).sub.3 (.092) 1.0 THF/55.degree./16h 8873 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.035) Al(OC.sub.6 H.sub.4 Cl).sub.3 (.070) 1.0 THF/55.degree./5h 8174 Mo.sub.2 (OAc).sub.4 (.043) Al(OC.sub.6 H.sub.4 Cl).sub.3 (.172) 1.8 THF/55.degree./18h 16__________________________________________________________________________ TABLE IV__________________________________________________________________________Attempted 3-Heptyne Metathesis Reactions2 EtC.tbd.CPr EtC.tbd.CEt + PrC.tbd.CPrEx. Component (i) Component (ii) Alkyne PercentNo. (mmoles) (mmoles) mmoles Conditions Metathesis__________________________________________________________________________75 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.044) -- 1.0 THF/55.degree./5h na76 Mo.sub.2 Cl.sub.2 (THF).sub.2 (OAc).sub.2 (.024) -- 1.0 ClBz/55.degree./16h na77 Mo.sub.2 Cl.sub.2 (PPh.sub.3).sub.2 (OAc).sub.2 (.027) -- 1.0 THF/55.degree./16h na78 Mo.sub.2 Cl.sub.4 (DPPM).sub.4 (.015) -- 1.0 THF/55.degree./16h na79 Mo.sub.2 (OAc).sub.4 (.047) -- 7.6 ClBz/55.degree./18h na80 [Mo.sub.2 (THF).sub.2 (OAc).sub.2 ][CF.sub.3 SO.sub.3 ].sub.2 --045) 1.0 THF/55.degree./18h na81 [Mo.sub.2 (CH.sub.3 CN).sub.4 (OAc).sub.2 ][CF.sub.3 SO.sub.3 ].sub.2 (.022) -- 2.4 THF/55.degree./18h na82 W.sub.2 (O.sub.2 CCF.sub.3).sub.4 (.018) -- 1.0 THF/55.degree./5h na__________________________________________________________________________

It will be appreciated that the values for the percent metathesis given in Tables II and III above (and in Table V hereinafter) were developed in the same fashion as the values presented in Table I. In other words, using the vpc area percent data on the reaction products, the sum of the quantities of the products formed was divided by the quantity (or quantities) of the initial acetylenic reactant(s) remaining in the product, and this value was multiplied by 100.

As previously noted above, acetylenic compounds containing functional substituents can be metathesized with the catalysts of this invention so long as the substituents do not prevent the reaction from taking place. As a rule of thumb, the more remote the substituent is from the acetylenic triple bond, the less influence it is likely to exert on the reaction. For example, a halogen atom in the beta position relative to the triple bond inhibits metathesis. On the other hand, halogen in the gamma position has been found relatively innocuous to metathesis.

Table V summarizes the results of a group of runs in which various functionalized acetylenic compounds were successfully metathesized pursuant to this invention using the complex Mo.sub.2 (OAc).sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 as the catalyst. The same general experimental procedure was used as described above with reference to the runs reported in Tables I through IV.

TABLE V__________________________________________________________________________Metathesis of Functionalized AcetylenesEx. Functionalized mmoles of PercentNo. Functional Group Acetylenic Compound(s) Used (mmoles) Catalyst Conditions Metathesis__________________________________________________________________________83 Conjugated olefin 2-methyl-1-hepten-3-yne (1.0) 0.018 MDC/32.degree./18h 1084 Nonconjugated olefin 1-nonen-4-yne (1.0) 0.014 THF/32.degree./18h 1885 Nonconjugated olefin 1-nonen-4-yne (1.0) 0.014 ClBz/32.degree./18h 8986 Methyl ether 1,4-dimethoxy-2-butyne (1.0) & 3-hexyne (1.0) 0.011 ClBz/32.degree./72h 10087 Phenyl ether 1,4-diphenoxy-2-butyne (0.5) & 3-hexyne (0.5) 0.011 THF/32.degree./72h 6088 Thiophenyl ether 1,4-dithiophenoxy-2-butyne (0.4) & 0.012 THF/32.degree./18h ca50 1,4-dimethoxy-2-butyne (1.0)89 Thiophenyl ether 1,4-dithiophenoxy-2-butyne (0.4) & 0.011 THF/70.degree./18h na 3-hexyne (1.0)90 Substituted aniline 1,4-di-(2,6-diisopropylanilino)-2-butyne (0.4) 0.012 THF/70.degree./18h ca50 3-hexyne (1.0)91 Substituted aniline 1,4-di-(2,6-diisopropylanilino)-2-butyne (0.4) 0.012 THF/70.degree./24h ca50 1,4-dimethoxy-2-butyne (1.0)92 Gamma-chloride 1-chloro-4-octyne (1.0) 0.013 ClBz/65.degree./18h 10093 Gamma-cyano 1-cyano-4-octyne (1.0) 0.020 THF/70.degree./48h 4194 Acetoxy 1,4-diacetoxy-2-butyne (1.0) & 3-heptyne (0.5) 0.015 ClBz/32.degree./120h na95 Acetoxy 1,4-diacetoxy-2-butyne (1.0) & 0.013 THF/70.degree./72h 20 1,4-dimethoxy-2-butyne (1.0)96 Acetoxy 1-acetoxy-3-heptyne (1.0) & 0.025 THF/70.degree./48h trace 1,4-dimethoxy-2-butyne (1.0)97 Trialkylsiloxy 1-tert-butyldimethylsiloxy-3-heptyne (1.0) 0.015 THF/60.degree./4h 37__________________________________________________________________________

The products formed in the Examples given in Table V are as follows:

______________________________________Ex. No. Product(s)______________________________________83 2,5-dimethyl-1,5-hexadien-3-yne and 4-octyne84 1,7-octadien-4-yne and 5-decyne85 1,7-octadien-4-yne and 5-decyne86 1-methoxy-2-pentyne87 1-phenoxy-2-pentyne88 l-methoxy-4-thiophenoxy-2-butyne (and oligomer)89 no reaction observed90 1-(2,6-diisopropylanilino)-2-hexyne91 1-(2,6-diisopropylanilino)-4-methoxy-2-butyne92 1,8-dichloro-4-octyne and 4-octyne93 1,8-dicyano-4-octyne and 4-octyne94 no reaction observed95 1-acetoxy-4-methoxy-2-butyne96 5-acetoxy-1-methoxy-2-pentyne and 1-methoxy-2-hexyne97 1,6-bis(tert-butyldimethylsiloxy)-3-hexyne and 4-octyne______________________________________

It is interesting to compare the results of Example 88 with Example 89 and of Example 95 with Example 94. In both cases the methoxy-substituted alkyne rendered the mixture amenable to co-metathesis whereas an unsubstituted alkyne did not. Other alkynes which did not metathesize under the conditions tested were 1-acetoxy-3-heptyne, a mixture of 3-heptyn-1-ol and 3-heptyne, 1-trimethylsiloxy-3-heptyne, a mixture of 1-trimethylsiloxy-3-heptyne and 1,4-dimethoxy-2-butyne, a mixture of tetrahydropyranyl-3-heptyne and 1,4-dimethoxy-2-butyne, a mixture of 1,4-dichloro-2-butyne and 1,4-dimethoxy-2-butyne, a mixture of 1-dimethylamino-2-pentyne and 1,4-dimethoxy-2-butyne, a mixture of 1-trimethylsilyl-1-propyne and 1,4-dimethoxy-2-butyne, a mixture of methyl 2-hexynoate and 1,4-dimethoxy-2-butyne, a mixture of 1-bromo-1-heptyne and 1,4-dimethoxy-2-butyne, and a mixture of 1-methoxy-1-octyne and 1,4-dimethoxy-2-butyne.

It can be seen from the foregoing that a wide variety of additional novel complexes may be produced and utilized as metathesis catalysts in accordance with this invention. A few additional exemplary materials include:

Mo.sub.2 (OAc).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.9 H.sub.19).sub.4 ].sub.2 Mo.sub.2 (O.sub.2 CCMe.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.5 H.sub.11).sub.4 ].sub.2 Mo.sub.2 (O.sub.2 CCF.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.5 H.sub.11).sub.4 ].sub.2 W.sub.2 (OAc).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.2 H.sub.5).sub.4 ].sub.2 W.sub.2 (O.sub.2 CCMe.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.5 H.sub.11).sub.4 ].sub.2 W.sub.2 (O.sub.2 CCF.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.5 H.sub.11).sub.4 ].sub.2 MoCr(OAc).sub.2 [Al(OC.sub.6 H.sub.5).sub.4 ].sub.2 MoCr(OAc).sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 MoCr(OAc).sub.2 [Al(OC.sub.6 H.sub.4 CH.sub.3).sub.4 ].sub.2 MoCr(OAc).sub.2 [Al(OC.sub.6 H.sub.4 C(CH.sub.3).sub.3).sub.4 ].sub.2 MoCr(O.sub.2 CCMe.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.2 H.sub.5).sub.4 ].sub.2 MoCr(O.sub.2 CCF.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.5 H.sub.11).sub.4 ].sub.2 WCr(OAc).sub.2 [Al(OC.sub.6 H.sub.5).sub.4 ].sub.2 WCr(OAc).sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 WCr(OAc).sub.2 [Al(OC.sub.6 H.sub.4 CH.sub.3).sub.4 ].sub.2 WCr(OAc).sub.2 [Al(OC.sub.6 H.sub.4 C(CH.sub.3).sub.3).sub.4 ].sub.2 WCr(O.sub.2 CCMe.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.2 H.sub.5).sub.4 ].sub.2 WCr(Ophd 2CCF.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.5 H.sub.1).sub.4 ].sub.2 MoW(OAc).sub.2 [Al(OC.sub.6 H.sub.5).sub.4 ].sub.2 MoW(OAc).sub.2 [Al(OC.sub.6 H.sub.4 Cl).sub.4 ].sub.2 MoW(OAc).sub.2 [Al(OC.sub.6 H.sub.4 CH.sub.3).sub.4 ].sub.2 MoW(OAc).sub.2 [Al(OC.sub.6 H.sub.4 C(CH.sub.3).sub.3).sub.4 ].sub.2 MoW(O.sub.2 CCMe.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.2 H.sub.5).sub.4 ].sub.2 MoW(O.sub.2 CCF.sub.3).sub.2 [Al(p-OC.sub.6 H.sub.4 C.sub.5 H.sub.11).sub.4 ].sub.2

One group of preferred complexes of this invention have the general empirical formula:

M.sub.2 (anion).sub.2 [Al(OR).sub.4 ].sub.2 where M is molybdenum or tungsten and the two M's are the same or are different from each other, anion is a monocarboxylic acid anion, and R is phenyl or a phenyl group substituted by alkyl or halogen radicals or both, and the three R's are the same or are different from each other.

Another group of preferred complexes of this invention have the general empirical formula:

M.sub.2 (anion).sub.2 [Al(OR).sub.4 ].sub.2 where M is molybdenum or tungsten and the two M's are the same or are different from each other, anion is a monocarboxylic acid anion, and R is an alkyl group substituted by cycloalkyl, aryl, halocycloalkyl, haloaryl or halogen radicals, and the three R's are the same or are different from each other.

Still other groups of preferred complexes are set forth in the foregoing disclosure and ensuing claims.

As this invention is susceptible to considerable variation in its practice without departing from its true spirit and scope, it is not intended that this invention be unduly limited to the exemplifications hereinbefore presented. Rather, what is intended to be embodied in the coverage of this invention is as set forth in the ensuing claims and the equivalents thereof.

Claims

1. In a process of catalytically metathesizing a metathesizable acetylene compound, the improvement in which the catalyst consists essentially of a catalyst formed from (i) a Group VI-B metal compound having (a) quadruple metal to metal bonds between a pair of Group VI-B metal atoms at least one of which has an atomic number above 24, and (b) four monovalent anions with a k.sub.A greater than 10.sup.-14, and (ii) a Group III-A phenoxide, Group III-A alkoxide, or IV-B metal alkoxide.

2. A process of claim 1 in which the catalyst consists essentially of a complex formed from (i) a molybdenum compound having (a) quadruple metal to metal bonds between a pair of molybdenum atoms, and (b) four monovalent anions with a k.sub.A greater than 10.sup.-12, and (ii) an aluminum trialkoxide, an aluminum triphenoxide, an alkylaluminum dialkoxide, or a titanium tetraalkoxide.

3. A process of claim 1 in which the catalyst consists essentially of a complex formed from (i) a tungsten compound having (a) quadruple metal to metal bonds between a pair of tungsten atoms, and (b) four monovalent anions with a k.sub.A greater than 10.sup.-12, and (ii) an aluminum trialkoxide, an aluminum triphenoxide, an alkylaluminum dialkoxide, or a titanium tetraalkoxide.

4. A process of claim 1 in which the catalyst consists essentially of a complex formed from (i) a molbdenum-tungsten compound having (a) quadruple metal to metal bonds between a pair of Group VI-B metal atoms, one of which is a molybdenum atom and the other of which is a tungsten atom, and (b) four monovalent anions with a k.sub.A greater than 10.sup.-12, and (ii) an aluminum trialkoxide, an aluminum triphenoxide, an alkylaluminum dialkoxide, or a titanium tetraalkoxide.

5. A process of claim 1 in which (ii) used in forming the catalyst is an aluminum phenoxide.

6. A process of claim 1 in which (ii) used in forming the catalyst is an aluminum triphenoxide.

7. A process of claim 1 in which the catalyst consists essentially of a complex of the general empirical formula:

M.sub.2 (anion).sub.2 [Al(OR).sub.4 ].sub.2

where M is molybdenum or tungsten and the two M's are the same or are different from each other, anion is a monocarboxylic acid anion, and R is phenyl or a phenyl group substituted by alkyl or halogen radicals or both, and the three R's are the same or are different from each other.

8. A process of claim 1 conducted in a liquid reaction medium.

9. A process of claim 1 conducted in a hydrocarbon, fluorocarbon, halogenated hydrocarbon or ether reaction medium.

10. A process of claim 1 conducted in a chlorinated hydrocarbon or ether reaction medium.

11. A process of claim 1 conducted in a chlorobenzene or methylene dichloride reaction medium.

12. A process of claim 1 further characterized by co-metathesizing at least two metathesizable acetylenic compounds in a liquid reaction medium.

13. A process of catalytically metathesizing one or more. metathesizable acetylenic compounds which comprises forming a catalyst from (i) a Group VI-B metal compound having (a) quadruple metal to metal bonds between a pair of Group VI-B metal atoms of atomic number above 24, and (b) four monovalent anions with a k.sub.A greater than 10.sup.-12, and (ii) a Group III-A phenoxide, Group III-A alkoxide, or Group IV-B metal alkoxide, and conducting the metathesis in the presence of the catalyst so that metathesis of the metathesizable acetylenic compound(s) takes place.

14. A process of claim 13 further characterized by forming said catalyst from (i) a Group VI-B metal compound having (a) quadruple metal to metal bonds between a pair of Group VI-B metal atoms of atomic number above 24, and (b) four monovalent anions with a k.sub.A greater than 10.sup.-12, and (ii) an aluminum phenoxide, an aluminum alkoxide or a titanium alkoxide, and performing the metathesis in an innocuous liquid reaction medium.

15. A process of claim 14 further characterized by forming said catalyst in a liquid reaction medium.

16. A process of claim 14 further characterized by co-metathesizing at least two metathesizable acetylenic compounds in the liquid reaction medium.