Copper-catalyzed benzylic C(sp3)–H alkoxylation of heterocyclic compounds

Abstract

We achieved intra- and intermolecular C(sp³)–H alkoxylation of benzylic positions of heteroaromatic compounds using CuBr_n (n = 1, 2)/5,6-dimethylphenanthroline (or 4,7-dimethoxyphenanthroline) and (^tBuO)₂ as a catalyst and an oxidant, respectively. The reaction proceeded at both terminal and internal benzylic positions of the alkyl groups. The intramolecular alkoxylation was performed on a gram scale.