Tris(pentafluorophenyl)borane [B(C6F5)3]-catalyzed Friedel-Crafts reactions of activated arenes and heteroarenes with α-amidosulfones: the synthesis of unsymmetrical triarylmethanes

Tris(pentafluorophenyl)borane [B(C6F5)(3)] has found to be an efficient catalyst for Friedel-Crafts reactions between activated arenes or heteroarenes and alpha-amidosulfones. The products undergo further Friedel-Crafts reactions with activated heteroarenes leading to the synthesis of unsymmetrical triarylmethanes. The present synthetic method displayed significant advantages such as low catalyst loading, mild reaction conditions, highly regioselective, high yield, and broad applicability to various substrates. (C) 2011 Elsevier Ltd. All rights reserved.