Catalysts for the asymmetric transfer hydrogenation of various ketones from [3-[(2S)-2-[(diphenylphosphanyl)oxy]-3-phenoxypropyl]-1-methyl-1H-imidazol-3-ium chloride] and [Ru(?6-arene)(?-Cl)Cl]2, Ir(?5-C5Me5)(?-Cl)Cl]2 or [Rh(?-Cl)(cod)]2
[ X ]
Tarih
2019
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science Sa
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
The combination of [3-[(2S)-2-[(diphenylphosphanyl)oxy]-3-phenoxypropyl]-1-methyl-1H-imidazol-3-ium chloride] with [Ru(eta(6)-arene)(mu-Cl)Cl](2), Ir(eta(5)-C5Me5)(mu-Cl)Cl](2) or [Rh(mu-Cl)(cod)](2), in the presence of KOH/isoPrOH, has been found to generate catalysts that are capable of enantioselectively reducing alkyl, aryl ketones to the corresponding (R)-alcohols. Under optimized conditions, when the catalysts were applied to the asymmetric transfer hydrogenation, we obtained the secondary alcohol products in high conversions and enantioselectivities using only 0.5 mol% catalyst loading. In addition, [3-[(2S)-2-{[(chloro(eta(4)-1,5-cyclooctadiene)rhodium)diphenyl phosphanyl] oxy}-3-phenoxypropyl]-1-methyl-1H-imidazol-3-ium chloride], (6) complex is much more active than the other analogous complexes in the transfer hydrogenation. Catalyst 6 acts as excellent catalysts, giving the corresponding (R)-1-phenyl ethanol in 99% conversion in 30 min (TOF <= 396 h(-1)) and in high enantioselectivity (92% ee).
Açıklama
Anahtar Kelimeler
Catalysis, Asymmetric Transfer Hydrogenation, Phosphinite-Cfils, Ruthenium, Rhodium, Iridium
Kaynak
Inorganica Chimica Acta
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
492
