Copper(I)-Catalyzed Cascade Synthesis of 2-Substituted 1,3-Benzothiazoles: Direct Access to Benzothiazolones

An efficient cascade process for the preparation of 2-substituted 1,3-benzothiazoles directly from 2-haloaryl isothiocyanates and O or S nucleophiles by a Cu-catalyzed, intramolecular, C-S bond formation has been developed. This cascade method is viable for the efficient syntheses of both O- and S-substituted 1,3-benzothiazoles. Furthermore, 1,3-benzothiazol-2(3H)-ones having an alkyl group allow easy access to 1,3-benzothiazolones. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)