Further insight in the minor/major concept using hydrogen pressure effect in asymmetric hydrogenation

• Published in: Journal of molecular catalysis. A, Chemical Chemical, 2012-11, Vol.363-364, p.214-222
• Main Authors: Aloui, A., Delbecq, F., Sautet, P., De Bellefon, C.
• Format: Article
• Language: English
• Subjects: (R,R)-Me-BPE; Asymmetric hydrogenation; Catalysis; Chemical and Process Engineering; Chemical engineering; Chemical Sciences; Chemistry; E-emap; Enantiomeric excess; Engineering Sciences; Exact sciences and technology; General and physical chemistry; Hydrogen pressure; M-acrylate; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2012.06.012

[Display omitted] ► Spectacular opposite hydrogen pressure effects on ee for one catalyst Rh/(R,R)-Me-BPE. ► Major-minor vs. key-and-lock principles domination depends on hydrogen pressure. ► Relation between hydrogen pressure effects on ee and substrate structure is discussed. ► Full set of kinetic constants provided for 2 catalytic systems. The catalytic system prepared from [Rh(COD)2]BF4 and (R,R)-Me-BPE provides a spectacular detrimental hydrogen pressure effect on ee from 94% down to 56% in the hydrogenation of methylacrylate, whereas it has a strong beneficial effect on the hydrogenation of E-emap (from 42% up to 72%). The kinetic parameters have been determined for both systems and have helped to identify the most enantioselective controlling steps (MECS). Accordingly, further explanations for the structure-ee and hydrogen pressure relationship are proposed.