Bifunctional AgOAc-catalyzed asymmetric [3+2] cycloaddition of azomethine ylides

[GRAPHICS] A bifunctional AgOAc-catalyzed asymmetric cycloaddition of azomethine ylides with electronic-deficient alkenes was developed using ferrocenyloxazoline-derived N,P ligands. The reactive metal-bound azomethine ylide dipole is formed by the deprotonation with acetate, and extra base is not necessary. The reactions proceed with high enantioselectivity. This method provides an efficient and convenient route to optically active pyrrolidine derivatives.