5535-49-9Relevant articles and documents
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Kopylova,B.V. et al.
, (1974)
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Electrophilic alkylation of pseudotetrahedral nickel(II) arylthiolate complexes
Deb, Tapash,Jensen, Michael P.
supporting information, p. 87 - 96 (2015/03/03)
A kinetic study is reported for reactions of pseudotetrahedral nickel(II) arylthiolate complexes [(TpR,Me)Ni-SAr] (TpR,Me = hydrotris{3-R-5-methyl-1-pyrazolyl}borate, R = Me, Ph, and Ar = C6H5, C6H4-4-Cl, C6H4-4-Me, C6H4-4-OMe, 2,4,6-Me3C6H2, 2,4,6-iPr3C6H2) with organic electrophiles R'X (i.e., MeI, EtI, BzBr) in low-polarity organic solvents (toluene, THF, chloroform, dichloromethane, or 1,2-dichloroethane), yielding a pseudotetrahedral halide complex [(TpR,Me)Ni-X] (X = Cl, Br, I) and the corresponding organosulfide R'SAr. Competitive reactions with halogenated solvents and adventitious air were also examined. Akin to reactions of analogous and biomimetic zinc complexes, a pertinent mechanistic question is the nature of the reactive nucleophile, either an intact thiolate complex or a free arylthiolate resulting from a dissociative pre-equilibrium. The observed kinetics conformed to a second-order rate law, first order with respect to the complex and electrophile, and no intermediate complexes were observed. In the absence of a mechanistically diagnostic rate law, a variety of mechanistic probes were examined, including kinetic effects of varying the metal, solvent, electrophile, and temperature, as well as the 3-pyrazolyl and arylthiolate substituents. Compared to zinc analogues, the effect of Ni-SAr covalency is also of interest herein. The results are broadly interpreted with respect to the disparate mechanistic pathways.
Oxo-rhenium(V) complexes containing heterocyclic ligands as catalysts for the reduction of sulfoxides
Sousa, Sara C. A.,Bernardo, Joana R.,Wolff, Mariusz,Machura, Barbara,Fernandes, Ana C.
, p. 1855 - 1859 (2014/04/03)
This work reports the catalytic activity of a large variety of oxo-rhenium(V) complexes (1 mol-%) containing the ligands 2-(2-hydroxy-5- methylphenyl)benzotriazole (Hhmpbta), 2-(2-hydroxyphenyl)benzothiazole (Hhpbt), 2-(2-hydroxyphenyl)benzoxazole (Hhpbo), and 2-(2-hydroxyphenyl)-1H-benzimidazole (Hhpbi) in the deoxygenation of sulfoxides with silanes or boranes as the reducing agents. In general, all of the complexes are excellent catalysts, although the PhSiH3/[ReOBr2(hmpbta)(PPh3)] and pinacolborane/[ReOBr2(hmpbta)(PPh3)] systems are the most efficient for the reduction of aromatic and aliphatic sulfoxides and tolerate different functional groups. Copyright
