Facile synthesis of 2-substituted benzo[ b ]furans and indoles by copper-catalyzed intramolecular cyclization of 2-alkynyl phenols and tosylanilines.

A catalytic amount of CuCl and Cs 2 CO 3 was employed to synthesize a variety of 2-substituted benzo[ b ]furans and indoles by an intramolecular cyclization of 2-alkynyl phenols and tosylanilines. This protocol features mild conditions, high yields and broad substrate scope, which makes it a practical method for the synthesis of 2-substituted benzo[ b ]furans and indoles.