Practical and Efficient Synthesis of (E)-(alpha),(beta)-Unsaturated Amides Bearing (S)-(alpha)-Methylbenzylamine from 2-Phosphonamides via Horner-Wadsworth-Emmons Reaction

The highly stereoselective synthesis of (E)-(alpha),(beta)-unsaturated amides bearing (S)-(alpha)-methylbenzylamine was achieved from 2phosphonamides via Horner-Wadsworth-Emmons reaction. The starting phosphonamides are easily prepared in two steps with ­excellent yields via the standard Arbuzov reaction of trimethyl­phosphite and (alpha)-bromoamides.