Aza-Wittig rearrangements and cyclizations by transmetallation of N-benzylaminomethylstannanes

Abstract

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 α-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.