Facile Access to Ring-Fused Aminals via Direct α-Amination of Secondary Amines with <i>ortho</i>-Aminobenzaldehydes. Synthesis of Vasicine, Deoxyvasicine, Deoxyvasicinone, Mackinazolinone and Ruteacarpine.

Abstract

Secondary amines undergo redox-neutral reactions with aminobenzaldehydes under conventional and microwave heating to furnish polycyclic aminals via amine α-amination/<i>N</i>-alkylation. This unique α-functionalization reaction proceeds without the involvement of transition metals or other additives. The resulting aminal products are precursors for various quinazolinone alkaloids and their analogues.