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-trimethylenepenta-1,4-dienyl tetrafluoroborate cation with N,N-dimethylaniline affords a mixture of products from the alkylation of N,N-dimethylaniline at the para-position by monomeric and linear and cyclic dimeric carbocations along with linear and cyclic dimers of 1,3-diferrocenylmethylene-2-methylenecyclohexane. These results confirm and illustrate a nonsynchronous cationic cyclodimerization mechanism for ferrocenylbuta-1,3-dienes.