The Research Of Palladium-catalyzed Asymmetric [3+2] Cycloadditions Of Vinylcyclopropanes And Aldimines

Pyrrolidine derivatives are abundant both in pharmaceuticals and in nature occurring compounds. These compounds are also widely employed the synthesis of complicated molecules. Therefore, much attention has been devoted to the rapid and efficient synthesis of pyrrolidine derivatives. With this regard, 1,3-dipolar cycloaddition of azomethine ylide and electron deficient olefins is one of the most efficient approach to these compounds. Herein, palladium catalyzed cycloaddition of vinyl cyclopropane dicarboxylate and aldimines are developed. In the reaction vinyl cyclopropane dicarboxylate was activated to form a transient zwitter ionic allyl palladium complex which further reacts with aldimines to form the optically and functionalized pyrrolidine derivatives in excellent yields and with up to 92% ee and up to 5 : 1 dr. The products are fully identified and the absolute configuration of predominantly formed isomer are determined by X-ray diffraction of the single crystal.