Organoselenium ligands are building blocks of several transition metal complexes which catalyze various organic reactions efficiently in solution. In this review the survey of developments pertaining to the designing of such complexes (along with their Se-ligands), and their uses as catalysts for various organic reactions has been presented with critical analysis of present status of the subject. Undoubtedly a new family of catalysts or their precursors has been generated by organoselenium ligands. The catalytic activity and selectivity of their metal complexes can sometimes be fine-tuned efficiently by changing the ligand's framework. They show good thermal and air-stability. This, coupled with ease in their handling and synthesis, may make them not only attractive but good alternatives to several popular catalysts.

Newly synthesized, air and moisture insensitive palladacycle [PdCl(L–H)] (L = (C₆H₅)(2-HOC₆H₄)CHNH(CH₂)₃SePh; a (N, Se, C ⁻) ligand) shows high catalytic activity for the Suzuki–Miyaura coupling reaction of phenylboronic acid with aryl/heteroaryl chlorides/bromides (TON for aryl chlorides up to 9200) and is converted to ∼8 nm size particles of Pd₁₇Se₁₅ (probably the real catalyst).

The new selenated Schiff bases L1–L4 which differ in the chain lengths (longest in L4) of non-coordinating substituents and their square planar complexes [Pd(L–H)Cl] (1–4) [L = L1–L4, behaving as (Se, N, O⁻) ligand] have been synthesized and characterized by multinuclei NMR. The molecular structure of 1 has been elucidated by X-ray diffraction on its single crystal [Pd–Se = 2.3965(9) Å]. All the complexes 1–4 (0.5 mol%) have been found suitable to catalyze Suzuki–Miyaura coupling reactions under mild conditions. The activity of 4 which has ligand L4 has been found highest. The formation of palladium(0) nano-particles (NPs) stablilized by organoselenium species appears to be the catalytic pathway. The length of the pendent alkyl chain present in the complex molecule unprecedentedly controls the dispersion and composition of these particles and consequently the catalytic activity.

Suzuki–Miyaura C–C cross coupling (SMC), an important synthetic strategy for many organic molecules, has several advantages such as mild reaction conditions, high tolerance toward various functional groups and ease in isolation of the product. Palladium(II) ligated with phosphines (particularly bulky and electron-rich) and N-heterocyclic carbenes (NHCs) has been found to be efficient in the catalysis of SMC. The drawback with many of these catalysts is their air/moisture sensitivity. Since 2000, palladium(II) complexes of organosulphur and related ligands have emerged as viable alternatives to palladium–phosphine/carbene complexes as they have sufficient thermal stability, air and moisture insensitivity. Moreover synthesis of complexes of such ligands is easy. In this perspective Suzuki–Miyaura C–C coupling reactions catalyzed with palladium(II)-complexes of organosulphur ligands have been reviewed. Catalysis of SMC with palladium(II) complexes of organoselenium and tellurium ligands, studied much less in comparison to those of organosulphur ligands, is also included.