Dual Photoredox and Copper Catalysis: Enantioselective 1,2-Amidocyanation of 1,3-Dienes
Dan Forster, Weisi Guo, Qian Wang, Jieping Zhu
Abstract
Dual photoredox–transition-metal catalysis has emerged as a powerful tool for the development of chemical transformations. However, its application in the selective difunctionalization of 1,3-dienes remains essentially unexploited. By the synergistic action of photoredox and copper catalysts, we report herein an enantioselective 1,2-amidocyanation of 1,3-dienes. Visible-light irradiation of a chloroform solution of conjugated dienes, N -Boc-amidopyridinium salts, and TMSCN in the presence of a catalytic amount of fac -Ir(ppy) 3, Cu(OTf) 2 · x H 2 O, and a chiral Box ligand affords three-component adducts in good to high yields with high regio- and enantioselectivities. A L*CuCN complex, fully characterized spectroscopically and confirmed by X-ray crystallographic analysis, is able to catalyze the transformation, therefore supporting an inner-sphere cyanide transfer pathway.