Development Of Novel Imine Ligands And Their Applications In Asymmetric Kinugasa Reaction

β-lactam is a series of core structural skeletons with important biologically active molecules,such as β-lactam antibiotics.β-lactam compounds also play important roles in organic synthesis.Among the many ways to synthesize β-lactam,copper-catalyzed asymmetric Kinugasa reaction is a simple and efficient method with many attractive advantages,therefore,the synthesis of optically pure β-lactam has always been a researcher one of the key topics of concern is also facing huge challenges.To solve this problem,we successfully developed a new class of chiral N,N,N-imine ligands derived from TsDPEN and applied them to copper-catalyzed asymmetric Kinugasa reaction.Under optimal conditions,we synthesized a series of cis β-lactams with moderate to good yields(up to 93%),excellent diastereoselectivities(up to 17.5: 1),and excellent enantioselectivities(Up to 91%).