Photocatalytic dehydrogenated etherification of 2-aryl benzylic alcohols

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, O 2 , n Bu 4 NBr and K 2 CO 3 in EtOH under visible-light irradiation. The late-stage application of this protocol to the synthesis of structurally complex 6 H -benzo[ c ]chromenes proves its synthetic utility. Here we describe an efficient and practical method for the conversion of 2-aryl benzylic alcohols into the corresponding chromenes with the synergistic interactions of 2-bromoanthraquinone, O 2 , n Bu 4 NBr and K 2 CO 3 under visible-light irradiation.