42157-57-3Relevant articles and documents
Iodine(III) Enabled Dehydrogenative Aryl C?S Coupling by in situ Generated Sulfenium Ion
Choudhuri, Khokan,Maiti, Saikat,Mal, Prasenjit
, p. 1092 - 1101 (2019/01/30)
Due to the normal polarity preferences, arenes form stable complexes with thiols through S?H???π interaction and direct dehydrogenative aryl C?S coupling is usually restricted. We report here an umpolung based one pot and direct C?S coupling approach unde
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.