Controllable chemoselectivity in the coupling of bromoalkynes with alcohols under visible-light irradiation without additives: synthesis of propargyl alcohols and α-ketoesters.

The chemoselectivity of visible-light-induced coupling reactions of bromoalkynes with alcohols can be controlled by simple changes to the reaction atmosphere (N-2 or O-2). A N-2 atmosphere favours propargyl alcohols via a direct C-C coupling process, whereas an O-2 atmosphere results in the generation of alpha-ketoesters through the oxidative C C/C-O coupling pathway.