Akademik Veri Yönetim Sistemi
JOURNAL OF ORGANOMETALLIC CHEMISTRY, cilt.997, ss.122791, 2023 (SCI-Expanded)
Herein, [Ru(NHC)( p -cymene)Cl 2 ] ( 3 ) and [MCl(NHC)(cod)] ( M = Rh ( 4 ) or Ir ( 5 )) (cod = 1,5–cyclooctadiene) complexes of a silyl–substituted N-heterocyclic carbene ligand (NHC) have been prepared by the trans- metalation reaction between Ag–NHC ( 2 ) and corresponding starting metal compound. The charac- terization of the complexes has been completed by NMR spectroscopy and elemental analyses. Solid state structures of Ag- ( 2 ) and Rh-NHC ( 4 ) have also been determined by single crystal X-ray analysis. [RhCl(NHC)(CO) 2 ] type bis -carbonyl complex ( 6 ) has also been prepared and CO stretching frequencies pointed the strong σ–donor ability of the silyl-substituted NHC. The catalytic activity of all complexes have been examined in hydrosilylation of terminal alkynes. Among the complexes, Ir-NHC has been found out as active catalyst with around 90% conversion and β–( Z ) selectivity at room temperature. Further studies revealed that this complex is able to maintain its stability in catalytic reaction conditions, chemos- elective to alkynes in the presence of alkenes, and operable in scale-up reactions. In contrast, bis -carbonyl Rh-NHC performed 82% β–( Z ) selectivity with full conversion of alkyne in first 4 h of reaction, but when reaction time was extended to 24 h, almost all β–( Z ) vinylsilane isomerised to thermodynamically more stable β–( E ).