Indole [1] and benzofuran [1d, 2] heterocycles are key structural units in a variety of biologically active natural products and unnatural synthetic materials. Over the last few years, transition-metal catalysts have been extensively used in the cyclization of o- alkynylarylamines [3a–l] and phenols [3m–p] to construct benzoheterocycles through intramolecular [3] and intermolecular reactions.[4] Many of these reactions required the ...
