Rhodium-catalyzed denitrogenative [2,3] sigmatropic rearrangement: An efficient entry to sulfur-containing quaternary centers

Chemical building blocks: α-Sulfenylated imines containing a quaternary center, an ubiquitous subunit and excellent building block, were achieved by rhodium-catalyzed denitrogenative [2,3] sigmatropic rearrangements of N-sulfonyl-1,2,3-triazoles with allylaryl(alkyl) sulfides. Coupling of this methodology with a copper-catalyzed cycloaddition reaction provides a platform for the direct regioselective functionalization of alkynes (see scheme; TC=thiophenecarboxylate; Ts=p-toluenesulfonyl). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.