Organoplatinum (II) complexes containing bis-(N-heterocyclic carbene) ligands: Catalytic activity in hydrosilylation of α,β-unsaturated ketones

Abstract

Two N-heterocyclic carbene platinum complexes [PtMe2(NHC)], 1 and [Pt(TFA)2(NHC)], 2, in which, NHC = 1, 1′- methylene- 3, 3′- bis[(N-(tert-butyl) imidazol-2- ylidene] have been prepared and characterized using NMR spectroscopy and ESI-MASS spectrometry. Reactivity of these complexes toward hydrosilylation of some α,β-unsaturated ketones investigated by NMR spectroscopy. Dimethyl bis-NHC platinum(II) complex shows good performance in comparison with those observed for trifluoroacetate bis-NHC platinum(II) complex, 2 in which higher efficiency and selectivity obtained with dimethyl complex 1 as catalyst. Although, the 1,2-additon and 1,4-addition pathways are possible, regiochemistry of the products show a 1, 4- addition is preferred pathway for these reactions.

Keywords

• organometallic chemistry
• platinum
• catalyst
• homogeneous
• hydrosylilation