Regioselective Nitrosocarbonyl Aldol Reaction of Deconjugated Butyrolactams: Synthesis of γ-Heterosubstituted α,β-Unsaturated γ-Lactams

The nitrosocarbonyl aldol reaction of deconjugated butyrolactams is developed employing quinidine as organocatalyst. The nitrosocarbonyl species generated in situ from hydroxamic acids react with a variety of deconjugated butyrolactams at room temperature, offering valuable α,β-unsaturated γ-lactams bearing heterosubstituted quaternary carbon center in very high yields. This nitrosocarbonyl aldol reaction is O-selective and proceeds exclusively at the γ-center of deconjugated butyrolactams. The reaction is scalable, accommodates diverse functional groups, and is also effective with azodicarboxylates.