Synthesis of Symmetric and Nonsymmetric NiII Thiophosphinito PECSP (E = S, O) Pincer Complexes and Their Applications in Kumada Coupling under Mild Conditions

Abstract

The reaction of 1,3‐dimercaptobenzene with iPr2PCl in the presence of the base NaH, furnishes the symmetric ligand [C6H4‐1,3‐(SPiPr2)2] (1a). The direct reaction of this ligand as well as of the literature‐known nonsymmetric ligand [C6H4‐1‐(SPiPr2)‐3‐(OPiPr2)] (1b) with NiCl2 affords the symmetric bis(thiophosphinito) PSCSP pincer complex [{C6H3‐2,6‐(SPiPr2)2}NiCl] (2a) as well as the phosphinito–thiophosphinito POCSP pincer complex [{C6H3‐2‐(SPiPr2)‐6‐(OPiPr2)}NiCl] (2b). Both complexes were fully characterised and their catalytic performance in Kumada coupling of aryl halides and p‐tolylmagnesium bromide under mild conditions was evaluated.