A palladium-catalyzed asymmetric 3 + 2 cycloaddition of vinylarylcyclopropanes (VACPs) with photogenerated ketenes is disclosed. This method efficiently constructs tetrahydrofurans featuring a quaternary stereocenter with high yields and excellent enantioselectivity (up to 99% ee). The reaction leverages a visible-light-induced Wolff rearrangement of α-diazoketones and employs a tailored chiral P,S-ligand. The aryl substituent on the VACP is proven crucial for achieving high stereocontrol. The protocol demonstrates broad substrate scope and synthetic utility, providing direct access to valuable tetrahydrofurans.
Ling et al. (Tue,) studied this question.