Aerobic copper-catalyzed synthesis of (E)-alkenyl sulfones and (E)-β-halo-alkenyl sulfones via addition of sodium sulfinates to alkynes

Copper-catalyzed sulfonylation of alkynes using sodium sulfinates in air produced regio- and stereo-selectively (E)-alkenyl sulfones. When a CuCl catalyst was employed, the hydrosulfonylation proceeded syn-selectively, and (E)-alkenyl sulfones were synthesized in excellent yields. In contrast, the reaction using CuI catalyst produced (E)-beta-haloalkenyl sulfones anti-selectively in the presence of potassium halides. Furthermore, the (E)-beta-bromoalkenyl sulfones are possible to convert into various alkenyl sulfones by Suzuki-Miyaura coupling. (C) 2014 Elsevier Ltd. All rights reserved.