Totally Chemo- and Regioselective Cobalt(I)-Mediated Formal Intermolecular Cyclotrimerization of Alkynes

Abstract

[reaction: see text] The first examples of totally chemo- and regioselective formal intermolecular cobalt(I)-catalyzed [2 + 2 + 2] cyclizations of three different alkynes are reported. The use of disposable silylated tethers in the sequence cyclization followed by the displacement of the silicon group led to polysubstituted arenes as a unique cycloadduct in high yields.