Asymmetric Cycloaddition Of Saturated Ester Compounds Catalyzed By Nitrogen Heterocyclic Carbenes

Chirality is one of the basic characteristics commonly found in nature.At the same time,chirality is widespread in natural materials in the natural world.Different chiral features of the same material have different physiological processes on living bodies,and they are based on the characteristics of the identification of vital organisms.Therefore,the study of chiral chemistry has profound implications for the development of medicine and pesticides.In recent years,N-Heterocyclic Carbene(NHC)catalysts have become a darling of organic small molecule catalysts.Its unique catalytic activation mode can not only achieve high stereoselectivity of the compounds synthesized by traditional methods,but also can synthesize novel structural compounds that ca nnot be synthesized by traditional methods.At present,NHC has been successfully used for the construction of C-C bond and C-X(X=O,S,N)bond,which provides a theoretical basis for the synthesis and screening of new and potentially active molecules.Carbonyl compounds are one of the most widely used raw materials in organic synthesis.However,the direct functionalization of the inert ?-sp3 carbon mainly depends on the catalysis of metal-based catalysts,and the direct functionalization of ?-sp3 carbons of saturated ketones or saturated aldehydes has been initially achieved through organic catalysts or photocatalysts.Currently,low-cost,readily available,and stable,high-level active occupation of the saturated ester compounds has been reported,but the activation of the ?-sp3 carbon(Lowest Unoccupied Molecular Orbital,LUMO)of saturated ester compo unds has not yet been reported.it is of great significance to realize LUMO activation of the ?-sp3 carbon of saturated ester compounds.Based on the direct activation and activation of ?-sp3 carbon of saturated esters catalyzed by azacyclic carbene,the LUMO activation of the ?-sp3 carbon of saturated esters was successfully achieved,and the one-step efficient construction of ?-lactams and ?-lactones was achieved simultaneously.Novel Synthesis of Chiral nitrogen-containing heterocyclic compound and a chiral macrolide compounds is an important theoretical and practical significance.