Devising artificial photoenzymes for abiological bond-forming reactions is of high synthetic value but also a tremendous challenge. Disclosed herein is the first photobiocatalytic cross-coupling of aryl halides enabled by a designer artificial dehalogenase, which features a genetically encoded benzophenone chromophore and site-specifically modified synthetic Ni II (bpy) cofactor with tunable proximity to streamline the dual catalysis. Transient absorption studies suggest the likelihood of energy transfer activation in the elementary organometallic event. This design strategy is viable to significantly expand the catalytic repertoire of artificial photoenzymes for useful organic transformations.

A (salen)­Mn­(III) complex was used as a biomimetic surrogate of the metallocofactor of phenol-oxidizing enzymes, in combination with chiral phosphoric acid relay catalysis, enabling an enantioselective direct oxidative phenol-indole [3 + 2] coupling reaction to access structurally diverse chiral benzofuroindolines. Differing from previous methods that exclusively make use of isolatable quinones or their imines, this system is capable of harnessing transient N-Boc quinone imines, and highlights its synthetic potential with high enantioselectivities, high step and atom economy, benign reaction conditions, and remarkable catalytic turnover for chiral phosphoric acid (CPA) (low to 0.01 mol %; up to 4100 turnover number (TON)).

No abstract