Photoenzymatically-Induced Asymmetric Hydroarylation of Alkenes with (Hetero)aryl Halides

Herein we describe a set of privileged and stereocomplementary ene-reductase enzymes which, when induced by light and aided by an exogenous photocatalyst, catalyze the coupling of (hetero)aryl halides and alkenes in an asymmetric intermolecular hydroarylation process. Thus, carbon scaffolds containing C(sp2)-C(sp3) bonds are synthesized enzymatically from simple precursors in excellent enantiomeric excess. Furthermore, an intramolecular coupling is achieved through tethering of (hetero)aryl halides to their alkene reaction partners and in this manner problematic side reactions are suppressed and yields improved. This work extends the utility of photo-induced biocatalysis through the addition of the novel and pharmaceutically important (hetero)aromatic halide class of radical precursors.