Reaction of N,N-dimethylaniline with 1,5-diferrocenyl-3-methyl-2,4-trimethylene-penta-1,4-dienyl carbocation. A nonsynchronous cationic cyclodimerization mechanism in conjugated dienes

Reaction of the 1,5-diferrocenyl-3-methyl-2,4-trimethylenpenta-1,4-dienyl t etrafluoroborate cation with N,N-dimethylaniline affords a mixture of produ cts from the alkylation of N,N-dimethylaniline at the para-position by mono meric and linear and cyclic dimeric carbocations along with linear and cycl ic dimers of 1,3-diferrocenylmethylene-2-methylenecyclohexane. These result s confirm and illustrate a nonsynchronous cationic cyclodimerization mechan ism for ferrocenylbuta-1,3-dienes.