Preformed molecular complexes of metals with organoselenium ligands: Syntheses and applications in catalysis

• Developments pertaining to the period 2012–2020. • Synthetic methodologies for catalytically relevant organoselenium ligands. • Selenium-ligated complexes of Pd, Ru, Rh, Ir, Zn, Ni, Cu, Ag, Au, Bi and Fe. • Synthetic methodologies and coordination aspects of catalytically useful complexes. • Application in the catalysis of 20 different chemical transformations. Organoselenium compounds have been used extensively as building blocks for the development of catalysts for several chemical transformations during the last two decades. During last 08 years, a large number of organoselenium ligands and their preformed molecular complexes with several metals (such as palladium, ruthenium, rhodium, zinc, copper, nickel, gold, silver, bismuth and iron) have been designed using different methods for the purpose of their application in catalysis. This review article covers the methodologies used in designing the organoselenium ligands and their catalytically active metal complexes designed during 2012–2020. Another major focus is on their application in the catalysis of a variety of chemical transformations including Suzuki coupling, Sonogashira coupling, Heck coupling, A 3 coupling reaction, allylation of aldehydes, C–H activation, C–O coupling, cross dehydrogenative coupling (CDC), C-S coupling, N -alkylation of anilines, transfer hydrogenation of carboxyl compounds, oxidation of alcohols, reduction of nitroarenes, ethylene oligomerization, C–N cleavage, conversion of aldehyde into amide, click reaction, multiple C–C bond formation reactions and hydrosilylation reactions of carbonyl compounds. A critical analysis of variation in catalytic performances and mechanistic aspects of catalysis has also been presented. Future perspectives have also been highlighted.