Template-directed synthesis of palladium(II) sulfonate-NHC complexes and catalytic studies in aqueous Mizoroki-Heck reactions

Abstract

Oxidation of easily accessible thiolato-functionalized dinuclear Pd(II) NHC complexes 1-3 by Oxone gave rise to sulfonate-NHC complexes 4-6. This represents the first template-directed approach to NHC complexes bearing sulfonate functions, where the sulfur atoms undergo a six-electron oxidation, changing their oxidation states from -II to +IV. The catalytic activities of water-soluble 4-6 were also tested in aqueous Mizoroki-Heck reactions. © 2014 American Chemical Society.