Ruthenium, thiolate complexes

In didiloromethane reaction of the ruthenium thiolate complex, [Ru(SPh)(CD)2(il5-Cp)], with one equivalent of the nitrosonium salt, NOPFg, results in oxidation of the thiolate ligand and precipitation of the dimer, [ Ru(CO)2(T 5-Cp) 2(li-HiSSPh)] pF6].39 Oxidation by NO - occurs also in the reaction O between the nickel(II) phosphine complexes, INiX2(PPh3)2] (X = Q, Br, NQ3), and NOQ in a mixture of benzene and cyclohexane. The reactions result in formation of the dimers, NiXQ(OPPh3)]2. 

Hu W, Luo Q, Ma X, Wu K, Liu J, Chen Y, Xiong S, Wang J, Sadler PJ, Wang F (2009) Arene control over thiolate to sulfinate oxidation in albumin by organometallic ruthenium anticancer complexes. Chem Eur J 15 6586-6594... 

The ruthenium hydride complex can be readily converted to a thiolate-containing product through S-H bond activation. ... 

The two-fold hydride addition to biaryl-thionolactone complexes followed by decomplexation of the generated ruthenium thiolates yielded the... 

Borylated pyrrole 88 was prepared by Oestreich by treatment of the corresponding pyrrole with pinacolborane and a ruthenium(II) thiolate complex. The direct synthesis of 88 promises to find wide utility in medicinal chemistry and was applied to a variety of substituted indoles (13JA10978). N-Methylpyrrole was directly arylated at room temperature by photoredox catalysis with diaryliodonium salts to furnish 89 in 84% yield (13SL507). 

In contrast to many studies on cycloaromatization via transition metal-vinylidene complexes as key reactive intermediates, only one example of such a reaction via transition metal-allenylidene complexes has been reported to date. In 2008, Yada et al. reported the formation of substituted fiirans 78 from 3-butyne-l,2-diols 77 in the presence of a catalytic amount of thiolate-bridged diruthenium complex (Scheme 21.33) [45]. This methodology was also applied to the formation of a substituted pyrrole 80 from l-amino-2-butyn-2-ol 79. It is noteworthy that thiolate-bridged diruthenium complexes worked as effective catalysts toward cyclization involving both ruthenium-allenylidene and ruthenium-vinylidene complexes as key reactive intermediates. 

Another method for reductive dimerization has been developed in hy-drosilylation. NiCl2-SEt2 is an effective catalyst in silylative dimerization of aromatic aldehydes with a hydrosilane (Scheme 12) [40]. A catalytic thiolate-bridged diruthenium complex [Cp RuCl(/ 2-SPrI)2RuCp ][OTf] also induces the conversion to 1,2-diaryl-1,2-disiloxyethane [41]. A dinuclear (siloxyben-zyl)ruthenium complex is considered to be formed, and the homolytic Ru - C bond fission leads to the siloxybenzyl radicals, which couple to the coupling product 14. 

Fig. 22. Remarkable activation-by-ligand-oxidation pathways for the reaction of ruthenium-arenes with thiolates. (a) Reaction of [Ru (r 6-bip)(en)(OH2)]+ with GSH (b) direct synthesis of ruthenium-arene sulfenato complexes (c) the air-stable thiolato complexes are oxidized in the presence of the antioxidant GSH.

The nature of the bridging thiolate ligands or the replacement of a terminal chloride ligand by water did not have much effect on the catalytic activity, complexes 105b-d and 106a,b being also operative in these transformations. In contrast, conventional monometallic ruthenium derivatives, as well as diruthenium complexes having no Ru-Ru bond, did not work at all. 

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