Lithium bis-catechol borate as an effective reductive quencher in photoredox catalysis.

The use of lithium bis-catechol borate (LiB(cat)2) as a reductive quencher for the photoredox mediated intermolecular C-H functionalization of various heteroaromatics with bromopyrroloindolines is described. LiB(cat)2 offers a financial benefit over state-of-the-art quenchers currently in use while eliminating the side reactions that typically plague these couplings. The advantage of this methodology is highlighted by the synthesis of C3-C2' (-) gliocladin C. Furthermore, additional examples of reactivity with various bromopyrroloindolines sets the stage for expedient routes towards other pharmaceutically active hexahydropyrroloindoline alkaloids and their analogues.