K3po4-Catalyzed Regiospecific Bromoamidation Of Beta, Beta-Dicyanostyrene Derivatives With N-Bromoacetamide(Nba)

An efficient method for the bromoamidation of beta, beta-dicyanostyrene derivatives with N-bromoacetamide (NBA) was developed. This protocol provides a convenient process to convert beta, beta-dicyanostyrene derivatives into the vicinal haloamines in excellent yields(up to 99%) at room temperature in the presence of anhydrous K3PO4 as a catalyst without the protection of the inert gaseous in CH2Cl2. A total of 11 examples were investigated and all the products showed the regionspecific feature. Based on the observation of different activities for the different substrates involving the electron-rich or electron-deficient beta, beta-dicyanostyrenes, a possible Michael addition mechanism was proposed.