Visible light bromide catalysis for oxazoline, pyrrolidine, and dihydrooxazine syntheses via Csp3–H functionalizations

Abstract

A catalytic benzylic C_sp³–H functionalization protocol is described here. This visible light-mediated process is centered on the utilization of a bromide catalyst and oxidant to generate a nitrogen (N)-centered radical for a site-selective hydrogen atom transfer (HAT) process. This strategy enabled the unconventional syntheses of a number of N-heterocycles dependent on the amide identity. We also discovered a nucleophilicity-dependent kinetic resolution for stereochemical differentiation of C_sp³–H bonds that enabled the stereoselective synthesis of cis- and trans-oxazolines.