Metal Free Bi(hetero)aryl Synthesis: A Benzyne Truce-Smiles Rearrangement

Abstract

A new benzyne transformation is described that affords versatile biaryl structures without recourse to transition-metal catalysis or stoichiometric amounts of organometallic building blocks. Aryl sulfonamides add to benzyne upon fluoride activation, and then undergo an aryl Truce-Smiles rearrangement to afford biaryls with sulfur dioxide extrusion. The reaction proceeds under simple reaction conditions and has excellent scope for the synthesis of sterically hindered atropisomeric biaryl amines. All smiles: Metal-free biaryl synthesis is achieved by adding benzyne to arylsulfonamides. A Smiles rearrangement enables C-C bond formation, thus accessing a variety of functionalized biaryls under mild reaction conditions.