The thermal rearrangement of allyl- and pentadienyl-ammonio-amidates. Evidence for competing but distinct concerted and radical mechanisms

Abstract

The allyl-N-acylammonio-amidates (1) rearrange by competing [1,2] and [3,2] shifts and the reactions show similar solvent and substituent effects; nevertheless, the rearrangement reactions of pentadienyl-N-acylammonio-amidates (4) show that the [1,2] rearrangement proceeds entirely by a non-concerted process involving radicals, whereas the [3,2] rearrangement involves a different mechanism which could be a concerted pericyclic process.