Ruthenium, rhodium and iridium complexes of a silyl-substituted N-heterocyclic carbene ligand and their catalytic performance in hydrosilylation of terminal alkynes


Mumcu A., Karataş M. O., Özdemir N., Erdoğan A., Küçükbay H.

JOURNAL OF ORGANOMETALLIC CHEMISTRY, cilt.997, ss.122791, 2023 (SCI-Expanded)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 997
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1016/j.organchem.2023122791
  • Dergi Adı: JOURNAL OF ORGANOMETALLIC CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, Chimica, Compendex
  • Sayfa Sayıları: ss.122791
  • İnönü Üniversitesi Adresli: Evet

Özet

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 ).