Decatungstate as Direct Hydrogen Atom Transfer Photocatalyst for SOMOphilic Alkynylation

Org Lett. 2021 Mar 19;23(6):2243-2247. doi: 10.1021/acs.orglett.1c00381. Epub 2021 Mar 3.

Abstract

A versatile approach for the alkynylation of a variety of aliphatic hydrogen donors, including alkanes, is reported. We used tetrabutylammonium decatungstate as photocatalyst to generate organoradicals from C-H/Si-H bonds via hydrogen atom transfer. The latter intermediates underwent SOMOphilic alkynylation by methanesulfonyl alkynes to afford internal alkynes upon loss of a sulfonyl radical. The effect of different radicofugal groups on the reaction outcome was evaluated and rationalized via a combined experimental and computational approach.