Bimolecular formation of radicals by hydrogen transfer, 11: Transfer hydrogenation of conjugated cyclic dienes and trienes

Article abstract of DOI:10.1002/jlac.199619961006

1,3-Cyclohexadiene, 1,3-cycloheptadiene and cycloheptatriene are smoothly hydrogenated to cyclohexene and cycloheptene, respectively, when heated to 260-340°C with an excess of 9,10-dihydroanthracene (DHA) in diphenyl ether or benzonitrile. On the basis of a mechanistic study a nonchain three-step mechanism is proposed which is initiated by a transfer of a hydrogen atom from DHA to the polyenes (retrodisproportionation). VCH Verlagsgesellschaft mbH, 1996.