New Method for Asymmetric Synthesis by Using Chiral Bases

烯醇酸离子的对映选择性合成和反应是现代合成化学的重要领域之一。本项目的目的是设计和合成多齿类型的手性锂酰胺类化合物和相应的手性胺类化合物，将其应用于手性锂烯醇酸酯的不对称合成和前手性锂烯醇酸酯的不对称反应，并将这些反应发展到高度催化体系。通过这个项目，我们得到了以下结果：(1)通过催化量的手性胺和化学计量的非手性锂酰胺相结合，实现了前手性酮的催化不对称去质子化反应。(2)新的C_2对称手性四胺被发现是催化α，α-二取代酮衍生的锂的不对称烷基化反应的优良配体。(3)利用催化量的手性四胺和几乎不溶于所用溶剂的质子源，实现了前手性酮的不对称质子化反应。(4)利用手性四胺实现了无环酮的不对称Michael选择性反应。

Enantioselctive synthesis and reactions of enolate ions are one of the important area in modern synthetic chemistry. The aim of this project is the design and synthesis of multidentate-type chiral lithium amides and the corresponding chiral amines, their applications to the enantioselective synthesis of chiral lithium enolates and to the enantioselective reactions of prochiral lithium enolates, and the development of these reactions to highly catalytic systems. We obtained the following results through this project.(1) The combination of a catalytic amount of a chiral amine and a stoichiometric amount of an achiral lithium amide has realized catalytic asymmetric deprotonation reactions of prochiral ketones.(2) The new C_2 symmetric chiral tetraamine has been found to be an excellent ligand for catalytic asymmetric alkylation of lithium enolates derived from alpha, alpha-disubstituted ketones.(3) Catalytic asymmetric protonation of prochiral ketones has been realized by using a catalytic amount of chiral tetraamine and a proton source which is hardly soluble in the solvent used.(4) Enantioselective Michael reactions of acyclic ketones have been realized by using a chiral tetraamine.