Solvent-dependent competitive rearrangements of cyclic tertiary propargylamine N-oxides

In protic media, cyclic propargylamine N-oxides 1 undergo solvent-dependent competitive rearrangements leading to enamino aldehydes 5, acrylamides 3, and secondary amines 4. The ratios of the products are evaluated and the possible mechanism of the competing reactions is interpreted by reaction kinetics studies and ab initio calculations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)