The catalytic activity of new iridium(I) N-heterocyclic carbene complexes for hydrogen transfer reaction of ketones

KARACA E. Ö.

MONATSHEFTE FUR CHEMIE, cilt.152, sa.2, ss.287-293, 2021 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 152 Sayı: 2
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1007/s00706-021-02734-6
  • Dergi Adı: MONATSHEFTE FUR CHEMIE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core
  • Sayfa Sayıları: ss.287-293
  • Anahtar Kelimeler: Iridium-NHC complexes, Carbenes, Hydrogen transfer, Benzimidazole, Alcohols
  • İnönü Üniversitesi Adresli: Evet

Özet

In this paper, the reaction of [Ir(COD)Cl](2) with in situ prepared Ag-N-heterocyclic carbene (NHC) complexes yields a series of [IrCl(COD)(NHC)] complexes. All compounds were fully characterized by H-1 NMR, C-13 NMR, and FT-IR spectroscopy. The manuscript focused on the preparation of new Ir-NHC complexes, characterization and catalytic behavior. A series of hydrogenation transfer reactions were performed to reveal the effects of the Ir-NHC complexes. The new Ir-NHC complexes of benzimidazole-2-ylidene are effective catalysts for the transfer of hydrogenation of different ketones, using i-PrOH as the source of hydrogen in the presence of KOH. The reactions were conducted at a substrate/catalyst/base (S/C/base) molar ratio of 1:0.001:2. Although all of the complexes are active catalysts for the transfer hydrogenation of ketones, moderate yields were obtained with acetylnaphthalene and conversion was not observed with very substituted ketones such as 2 ',3 ',4 ',5 ',6 '-pentamethylacetophenone. It was observed that for transfer hydrogenation reactions Ir-NHC catalysts were more active, compared to Ru-NHC catalyzed studies performed by our team. Graphic abstract