Synthesis of Diastereoenriched α‐Aminomethyl Enaminones via A Brønsted Acid‐Catalyzed Asymmetric aza‐Baylis‐Hillman Reaction of Chiral N‐Phosphonyl Imines

An effective chiral GAP methodology for preparing alpha-aminomethyl enaminones through a (R)-CSA-catalyzed asymmetric aza-Baylis-Hillman reaction is reported. Excellent yields and high diastereoselectivity could be obtained under mild conditions and convenient GAP techniques. The confirmations of the absolute configuration of N-phosphonyl imine and chiral enaminone by X-ray diffraction provides an explicit explanation of the chirality mechanism for GAP chemistry.