Phase-Transfer-Catalyzed Asymmetric Aza-Henry Reaction Using N-Carbamoyl Imines Generated In Situ from alpha-Amido Sulfones

A general approach to the catalytic asymmetric aza-Henry reaction has been developed. The combination of a commercially available phase-transfer catalyst (PTC) with a base is able to promote the in situ formation of N-carbamoyl imines from α-amido sulfones and activate nitromethane towards the asymmetric addition reaction, thus furnishing N-carbamoyl-protected β-nitroamines in good yields and with up to 98 % ee (see scheme; PG=protecting group).