Organosulfur, organoselenium, and organotellurium ligands in the development of palladium, nickel, and copper-based catalytic systems for Heck coupling

Abstract

During the last two decades, several research groups across the globe have utilized organochalcogen compounds as: (i) ligands for developing homogeneous, i.e. chalcogen-ligated metal complexes, and heterogeneous catalytic systems; (ii) stabilizers for developing metal nanocatalytic systems (iii) building blocks of single-source precursors for nanosized metal chalcogenides. The electron-donating abilities of chalcogen (S, Se, and Te) donors make them promising in the field of phosphine-free catalysis. Generally, such ligands and catalytic systems are easily synthesizable. In the preceding decade (2011–2020), a variety of homogeneous, heterogeneous, and nanocatalytic systems have been developed using organosulfur, organoselenium, and organotellurium ligands. Such catalytic systems have been extensively used for the Heck coupling reaction. This perspective article covers the synthetic methodologies used for such ligands and catalytic systems designed during 2012–2020. Another major focus of this article is the catalysis of Heck coupling with such systems. The substrate scope, green catalysis, use of conventional and non-conventional sources of energy, and catalytic performances are analysed and covered. The effects of the operational parameters of reactions have also been discussed. Various factors that influence the catalytic efficiencies have been highlighted, and the variations in the catalytic efficiencies of different catalytic systems have been critically analysed. The behaviours of the catalytic systems during the reactions have been summarized and correlated with mechanistic pathways. The catalytic cycles proposed for this reaction have also been paid sufficient attention.