Reductive Alkylation of 2-Bromoazoles via Photoinduced Electron Transfer: A Versatile Strategy to Csp2-Csp3 Coupled Products

Access to Csp(2)-Csp(3)-coupled products is a challenging goal at the forefront of catalysis. The photocatalytic reductive coupling of aryl bromides with unactivated alkenes is introduced as a convenient method that circumvents any need for synthesis of sp(3)-hybridized coupling partners. The reaction takes place via photoinduced electron transfer from a tertiary amine to an aryl bromide that fragments to provide an aryl radical and subsequently reacts with an alkene to form a C-C bond. Conveniently, the amine also serves as the final reductant. The method is operationally simple, functional group tolerant, and takes place with selectivities that will allow it to be used in the context of complex molecule synthesis.