SPS-Ni(II) pincer compounds of the type [Ni(phPS2)(P(C6H4-4-R)3)] Synthesis, characterization and catalytic evaluation in C-S cross-coupling reactions

The synthesis and characterization of a series of SPS-Ni(II) pincer complexes with different para-substituted triphenylphosphines has been performed. The molecular structure of [Ni(phPS(2))(PPh3)] (1) (phPS(2)H(2) = PhP(C6H4-2-SH)(2), bis(phenyl-2-thiol)phenylphosphine) was unequivocally determined by single crystal X-ray diffraction analysis. The metal centre exhibited a slightly distorted square planar geometry. The complexes showed a high catalytic activity in the C-S cross-coupling reaction of both alkyl-and aryl-disulfides with iodobenzenes for the production of non-symmetric sulfides. In general, the different para-substituted triphenylphosphine ligands do not affect the catalytic performance of the SPS-Ni(II) complexes. However, activity of the catalyst decreases with the steric hindrance of the different alkyl groups in the disulphide substrates. (C) 2017 Elsevier Ltd. All rights reserved.