SELECTIVE CATALYTIC HYDROGENATION OF 1,4-DIENES TO cis-MONOENES USING (NAPHTHALENE)(TRICARBONYL)CHROMIUM

Article abstract of DOI:10.1016/0022-328X(85)87006-6

Methylene interrupted dienes react with (naphthalene)(tricarbonyl)chromium under H2 to yield a mixture of positionally isomeric cis-monoene products.The isomer distribution, reactions with proposed organic intermediates, and kinetic studies suggest a mechanistic pathway that includes (1) loss of the arene from the metal fragment, (2) isomerization of the 1,4 diene to 1,3 conjugated dienes, and (3) subsequent reduction of the conjugated dienes to the isomeric cis-monoene products.The active metal fragment appeares to be selective in the isomerisation of 1,4 to 1,3 dienes and inert toward cis to trans geometrical isomerization of the monoene products.The results of kinetic studies using methyl cis,cis-9,12-octadienoate (methyl linoleate) as a substrate for the hydrogenation reactions are discussed.