Asymmetric transfer hydrogenation of acetophenone derivatives with novel chiral phosphinite based eta(6)-p-cymene/ruthenium(II) catalysts

• Published in: Journal of organometallic chemistry Vol. 696; no. 8; pp. 1541 - 1546
• Main Authors: Aydemir, Murat, Meric, Nermin, Baysal, Akin, Turgut, Yilmaz, Kayan, Cezmi, Seker, Sevil, Togrul, Mahmut, Gumgum, Bahattin
• Format: Journal Article
• Language: English
• Published: LAUSANNE Elsevier 15.04.2011
• Subjects: Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Physical Sciences; Science & Technology; AROMATIC KETONES; REACTIVITY; STYRENE; Asymmetric transfer hydrogenation; PROPAN-2-OL; Chiral phosphinite ligands; ARENE; ETHERS; LIGANDS; Homogeneous catalysis; Ruthenium(II) complexes; METAL-COMPLEXES; BIS(PHOSPHINITE)
• ISSN: 0022-328X
• DOI: 10.1016/j.jorganchem.2010.12.027

Enantioselective reduction of prochiral ketones to optically active secondary alcohols is an important subject in synthetic organic chemistry because the resulting chiral alcohols are extremely useful, biologically active compounds. The new chiral ligands (2R)-2-[benzyl{(2-((diphenylphosphanyl)oxy)ethyl)}amino]butyldiphenylphosphinite, 1 and (2R)-2-[benzyl{(2-((dicyclohexylphosphanyl)oxy)ethyl)}amino]butyldicyclohexylphosphinite, 2 and the corresponding ruthenium(II) complexes 3 and 4 have been prepared. The structures of these complexes have been elucidated by a combination of multinuclear NMR spectroscopy, IR spectroscopy and elemental analysis. P-31-{H-1} NMR, DEPT, H-1-C-13 HETCOR or H-1-H-1 COSY correlation experiments were used to confirm the spectral assignments. These ruthenium(II) ephosphinite complexes have been used as catalysts for the asymmetric transfer hydrogenation of acetophenone derivatives. Under optimized conditions, aromatic ketones were reduced in good conversions and in moderate to good enantioselectivities (up to 85% ee). (C) 2011 Elsevier B. V. All rights reserved.