Nickel/Photo-Cocatalyzed Asymmetric Acyl C–H Allylation of Aldehydes and Formamides
Rui Wang, Pei Fan, Chuan Wang
Abstract
Herein, we developed a highly enantioselective acyl C–H allylation of aldehydes and formamides, which proceeds under the cooperative catalysis of a chiral PHOX nickel complex and tetrabutylammonium decatungstate (TBADT). With readily available Morita–Baylis–Hillman adducts as the electrophilic allylating agent, the reported reaction allows for the synthesis of α-stereogenic β,γ-unsaturated 1,4-dicarbonyl compounds in a highly enantioselective manner. The preliminary mechanistic investigations point to an enantioconvergent reaction pathway, in which rapid kinetic resolution of the starting allyl acetates through oxidative addition to Ni(0) is followed by dynamic kinetic resolution of the resultant allyl Ni(II) complexes via the interaction with acyl radicals generated by TBADT-mediated homolytic acyl C–H bond cleavage.