Atropisomerism at CS Bonds: Asymmetric Synthesis of Diaryl Sulfones by Dynamic Resolution Under Thermodynamic Control

A powerful conformational preference exhibited by a diaryl sulfone axis lying ortho to a sulfinyl substituent enabled the dynamic resolution of atropisomeric diaryl sulfones under thermodynamic control (see scheme; e.r.=enantiomeric ratio). These compounds are the first resolvable compounds exhibiting atropisomerism at C-S bonds. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.