Enantioselective 1,4‐Reduction of Pyrimidin‐2‐ones to Synthesize Novel 3,4‐Dihydropyrimidin‐2(1H)‐ones Containing an Alkyl‐substituted Stereogenic Center

An efficient asymmetric 1,4‐reduction of pyrimidin‐2‐ones with a chiral phosphoric acid‐catalyzed system has been successfully developed, furnishing a series of chiral 3,4‐dihydro‐pyrimidin‐2‐one derivatives in excellent yields and enantioselectivities (up to 99% ee). Notably, this methodology enables a novel kind of chiral 3,4‐dihydropyrimidin‐2‐one with an alkyl stereogenic center to be prepared in high optical purity for the first time. An efficient asymmetric 1,4‐reduction of pyrimidin‐2‐ones with a chiral phosphoric acid‐catalyzed system, furnishing a novel kind of chiral 3,4‐dihydropyrimidin‐2‐one derivatives bearing alkyl‐substituted stereogenic center in excellent yields and enantioselectivities (up to 99% ee).