Merging Cu(I) and Cu(II) Photocatalysis: Development of a Versatile Oxohalogenation Protocol for the Sequential Cu(II)/Cu(I)-Catalyzed Oxoallylation of Vinylarenes

A sequential photocatalytic strategy is developed via the merger of Cu(II)/Cu(I)-catalytic cycles for oxoallylation vinyl arenes α-haloketones. The initial Cu(II)-photocatalyzed oxohalogenation exploits ligand-to-metal charge transfer (LMCT) to generate halide radicals from acyl halides utilizing air as a terminal oxidant and can be employed late-stage modification pharmaceuticals agrochemicals. α-Bromoketones obtained this way subsequently subjected one-pot Cu(I)-photocatalyzed allylation. This photocatalysis proceeds in highly regio- chemoselective fashion inconsequential electronic nature styrenes.