Tellurium-Empowered Catalysis for Enantioselective Seleno-Michael Addition Reaction

The development of a catalyst, which has not been explored before, not only provides an alternative to the existing organocatalysts but also leads to distinct chemical reactivity. Here, an organotellurium catalyst consisting of a quinine auxiliary displays notable activity for the enantioselective delivery of reactive organoselenols as a Michael donor under mild reaction conditions. The developed chiral organotellurium-catalyzed organoselenol addition to alkenes shows a broad substrate scope, as electron-rich and deficient arylselenols and diversely substituted enones are amenable to the reaction conditions. Control experiments, detailed 77 Se and 125 Te NMR suggest that chalcogen-bonded Te···Se interaction between the catalyst and organoselenol seems responsible for accelerated and highly enantioselective delivery of arylselenols to enones. The practically synthesized chiral organoselenides have also been readily post-derivatized by taking advantage of the leaving group ability and recyclability of arylselenium.