Remarkable Effects of Additives to Facilitate Aza-Mannich Type Reaction: A Rapid Access to (beta)-Amino Ketone O-Alkyl Oximes

Aza-Mannich-type reaction proceeded between imines and the aza-enolates formed from (alpha)-iodomethyl ketone O-alkyl oximes with titanium tetraiodide to give (beta)-amino ketone O-alkyl oximes in good to excellent yields. Remarkable effects of added ­silica gel or molecular sieves (4 (angstrom)) were observed to promote the addition reactions.