In recent years, there has been an increasing application of chiral selenium compounds as ligands in metal-catalyzed enantioselective transformations. One of the most important challenges in this field is the development of new chiral complexes (catalyst) generated from the reaction between a metal and appropriate chiral selenium-containing compounds (ligand). The vast majority of these ligands are easily synthesized in a few high-yielding synthetic steps, starting from readily available chiral amino alcohols. In this context, the advantages of using these compounds will be discussed, mainly with regard to their easy accessibility, modular nature and the formation of strong bonds with soft or, more rarely, hard metals. Important selective contributions within the field of chiral selenium complexes are examined, according to their applications. As final remarks, future developments and perspectives of the field are discussed.
Herein, we report an efficient, quick and eco-friendly new method for the synthesis of a variety of selenol esters. This novel solvent-free methodology gave good to excellent isolated yields of desired products after just 2 min under microwave irradiation. Furthermore, by using the same green approach, we were also able to synthesize selenocarbonates bearing interesting functionalities.
The efficient and mild copper-catalyzed synthesis of unsymmetrical diorganyl chalcogenides under ligand- and solvent-free conditions is described. The cross-coupling reaction was performed using aryl boric acids and 0.5 equiv. of diorganyl dichalcogenides (Te/Se/S) in the presence of 3 mol % of CuI and 3 equiv. of DMSO, under microwave irradiation. This new protocol allowed the preparation of several unsymmetrical diorganyl chalcogenides in good to excellent yields.