AZA-WITTIG REARRANGEMENTS AND CYCLIZATIONS BY TRANSMETALATION OF N-BENZYLAMINOMETHYLSTANNANES

Transmetallation of N-allyl-N-benzylaminomethylstannanes with butyllithium or methyllithium allows carbon-carbon bond formation by a [1,2]-rearrangement. Substantial amounts of the protodestannylated product are also produced. Transmetallation of the corresponding alpha-methyl substituted allylic amine or homoallylic amine gives an overall rearrangement by cyclization onto the olefin followed by recapture of the new carbanion by tetramethyltin.