Ruthenium complexes mercury ligands

Benzoselenadiazole (bsd) has been used as a ligand in the ruthenium complex [RuClH-(CO)(bsd)(PPh3)2]. This complex was used to catalyse the transalkynylation and catalytic demercuration of bis(alkynyl)mercurials <96CC1059>. 

Ruthenium complexes are often inexpensive, readily available, and active catalysts for the hydration of alkynes [177-179]. In contrast to most mercury and gold systems, several of the Ru-based catalysts displayed a propensity to generate the anti-Markovnikov hydration products. One of the more practical approaches to this anti-Markovnikov hydration chemistry was developed by Herzon (Scheme 2.115) [180]. His approach entailed the use of a ruthenium compound bearing a 5,5 -(bistrifluoromethyl)-2,2 -(bipyridine) as the supporting ligand. A variety of ruthenium complexes could be isolated, and at least one... 

Cofacial ruthenium and osmium bisporphyrins proved to be moderate catalysts (6-9 turnover h 1) for the reduction of proton at mercury pool in THF.17,18 Two mechanisms of H2 evolution have been proposed involving a dihydride or a dihydrogen complex. A wide range of reduction potentials (from —0.63 V to —1.24 V vs. SCE) has been obtained by varying the central metal and the carbon-based axial ligand. However, those catalysts with less negative reduction potentials needed the use of strong acids to carry out the catalysis. These catalysts appeared handicapped by slow reaction kinetics. 

---