Verfahren zur katalytischen Cyclo-Dimerisation von 1,3-Diolefinen

摘要

1,238,094. Cyclo-dimerizing dienes. FARBWERKE HOECHST A.G. 14 April, 1969 [13 April, 1968], No. 19073/69. Heading C5E. 1,3 - Diolefins are cyclodimerized by heating with a catalyst at 60-400‹ C. and 0-150 atmosphere (gauge) in the absence of hydrogen or other reducing agent to initiate the reaction, and then completing the reaction at 0-200‹ C., the catalyst comprising: (a) a cyclopentadienyl - nickel compound having one of the following formulµ in which R1 is alkyl or aryl n is zero or an integer from 1-5 X is a neutral ligand or an anion R2 is a phosphine or carbon monoxide m is 0 or 1 and in which neighbouring R1 radicals may be linked to one another to form a 6-membered ring fused to the cyclopentadienyl system, and (b) which may optionally be absent if R2 is a phosphine or phosphorus (III) compound which is phosphorous acid tripiperidide, or has one of the formula PR 3 , P(OR) 3 or P(NR 2 ) 3 in which R is alkyl, cyclohexyl, or aryl. Specific examples use the following catalyst components: (a) bis - (cyclopentadienyl) - nickel (II) bis - (ethyl - cyclopentadienyl) - nickel (II) allyl - (cyclopentadienyl) - nickel (II) triphenylphosphine - cyclopentadienylnickel (II) chloride cyclopentadienyl - nickel - nitrosyl dicyclopentadienyl - nickel - carbonyl (b) tri - (α - phenylphenyl) phosphite triphenyl phosphine tri - (o - phenyl - phenyl) phosphite tri - (o - methyl - phenyl) phosphite. Examples 1-6 relate to cyclodimerizing butadiene, the product usually predominating in cyclooctadiene - 1,5, though 4 - vinyl - cyclohexene - 1 is also produced in reasonable quantity and in Example 4 predominates. Example 7 converts pentadiene - 1,3 to dimethyloctadiene - 1,5.