BI-OAc-Accelerated C3–H Alkylation of Quinoxalin-2(1<i>H</i>)-ones under Visible-Light Irradiation

Abstract

An efficient, photoredox-catalyst-free radical alkylation of quinoxalin-2(1<i>H</i>)-ones has been described. This reaction utilizes 4-alkyl-1,4-dihydropyridines (R-DHPs) as alkyl radical precursors and acetoxybenziodoxole (BI-OAc) as an electron acceptor to undergo single-electron transfer with photoexcited R-DHPs. The benign conditions allow for good compatibility in the scope of both quinoxalin-2(1<i>H</i>)-ones and R-DHPs. The synthetic value of the protocol was also demonstrated by the successful functionalization of natural products and drug-based complex molecules.