Decatungstate-Mediated C(sp3 )-H Heteroarylation via Radical-Polar Crossover in Batch and Flow

Abstract

Photocatalytic hydrogen atom transfer is a very powerful strategy for the regioselective C(sp³ )-H functionalization of organic molecules. Herein, we report on the unprecedented combination of decatungstate hydrogen atom transfer photocatalysis with the oxidative radical-polar crossover concept to access the direct net-oxidative C(sp³ )-H heteroarylation. The present methodology demonstrates a high functional group tolerance (40 examples) and is scalable when using continuous-flow reactor technology. The developed protocol is also amenable to the late-stage functionalization of biologically relevant molecules such as stanozolol, (-)-ambroxide, podophyllotoxin, and dideoxyribose.

Keywords: TBADT; flow chemistry; heteroarylation; hydrogen atom transfer; radical-polar crossover.