Olefin Hydroarylation Catalyzed by (pyridyl-indolate)Pt(II) Complexes: Catalytic Efficiencies and Mechanistic Aspects

Benjamin A. Suslick†‡ , Allegra L. Liberman-Martin†‡§, Truman C. Wambach†‡, and T. Don Tilley*†‡
† Department of Chemistry, University of California, Berkeley, California 94720, United States
‡ Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States

ACS Catal., 2017, 7, pp 4313–4322
DOI: 10.1021/acscatal.7b01560
Publication Date (Web): May 18, 2017

A series of Pt(II) complexes of the type (N–N)PtPh(SR2) (N–N = 2,2′-pyridyl-indolate) were prepared, and their performance as catalysts for the hydroarylation of olefins was assessed. Evidence that the catalysis is homogeneous and is Pt-mediated is provided by control experiments with added hindered base (2,6-di-tert-butyl-4-methylpyridine) and Hg(0). Two potential catalytic intermediates, (tBuPyInd)PtPh(C2H4) and (tBuPyInd)Pt(CH2CH2Ph)(C2H4), were synthesized, and their catalytic efficacy was explored. Additionally, decomposition and deactivation pathways, including styrene formation via β-hydride elimination and ligand reductive demetalation, were identified.