Photocatalytic dehydrogenated etherification of 2-aryl benzylic alcohols

Abstract

Here we describe an efficient and practical method for the conversion of 2-aryl benzylic alcohols into the corresponding chromenes through visible-light-induced photoredox catalysis. This protocol has been applied to a wide range of benzylic alcohols, involving pharmaceuticals and natural products, with the synergistic interactions of 2-bromoanthraquinone, O₂, nBu₄NBr and K₂CO₃ in EtOH under visible-light irradiation. The late-stage application of this protocol to the synthesis of structurally complex 6H-benzo[c]chromenes proves its synthetic utility.