Synthesis of Ruthenium Hydride Complexes Containing beta-Aminophosphine Ligands Derived from Amino Acids and their use in the H2-Hydrogenation of Ketones and Imines

The new complexes RuHCl(PPh 2 CH 2 -CHRNH 2 ) 2 and RuHCl(PPh 2 CH 2 CHRNH 2 )(R-binap), R=H (Pgly), R=Me [(R)-Pala] were prepared by the substitution of the PPh 3 ligands in RuHCl(PPh 3 ) 3 or RuHCl(PPh 3 )[(R)-binap] with beta-aminophosphines derived from amino acids. The complex trans-RuHCl(Pgly)[(R)-binap] has been characterized by X-ray crystallography. The complex trans-RuHCl[(S)-Ppro] 2 where (S)-Ppro is derived from proline was also prepared and characterized by X-ray crystallography. These were used as catalyst precursors in the presence of a base (KOPr-i or KOBu-t) for the hydrogenation of various ketones and imines to the respective alcohols and amines with H 2 gas (1-11 atm) at room temperature. Acetophenone was hydrogenated to (S)-1-phenylethanol in low ee (up to 40%) when catalyzed by the enantiomerically pure complexes. These complexes are especially active in the hydrogenation of sterically congested and electronically deactivated ketones and imines and are selective for the hydrogenation of C=O bonds over C=C bonds.

[1]  R. Morris,et al.  Mechanisms of the H2-hydrogenation and transfer hydrogenation of polar bonds catalyzed by ruthenium hydride complexes , 2004 .

[2]  R. Morris,et al.  Hydrogenation versus transfer hydrogenation of ketones: two established ruthenium systems catalyze both. , 2003, Chemistry.

[3]  R. Noyori,et al.  Mechanism of asymmetric hydrogenation of ketones catalyzed by BINAP/1,2-diamine-rutheniumII complexes. , 2003, Journal of the American Chemical Society.

[4]  A. Chan,et al.  Chiral [RuCl2(dipyridylphosphane)(1,2‐diamine)] Catalysts: Applications in Asymmetric Hydrogenation of a Wide Range of Simple Ketones , 2003 .

[5]  B. Pugin,et al.  Selective Hydrogenation for Fine Chemicals: Recent Trends and New Developments , 2003 .

[6]  J. Henschke,et al.  Enantioselective Hydrogenation of Imines Using a Diverse Library of Ruthenium Dichloride(diphosphine)(diamine) Precatalysts , 2003 .

[7]  Robert H Morris,et al.  Mechanism of the hydrogenation of ketones catalyzed by trans-dihydrido(diamine)ruthenium II complexes. , 2002, Journal of the American Chemical Society.

[8]  P. Sadler,et al.  Chelate ring-opening aminophosphine complexes of ruthenium(II) , 2002 .

[9]  R. Morris,et al.  Catalytic cycle for the asymmetric hydrogenation of prochiral ketones to chiral alcohols: direct hydride and proton transfer from chiral catalysts trans-Ru(H)(2)(diphosphine)(diamine) to ketones and direct addition of dihydrogen to the resulting hydridoamido complexes. , 2001, Journal of the American Chemical Society.

[10]  V. F. Kuznetsov,et al.  Chiral Ruthenium Complexes with P,N-Ligands Derived from (S)-Proline , 2001 .

[11]  R. Morris,et al.  RuHCl(diphosphine)(diamine): Catalyst Precursors for the Stereoselective Hydrogenation of Ketones and Imines1 , 2001 .

[12]  Ryoji Noyori,et al.  Asymmetric Catalysis by Architectural and Functional Molecular Engineering: Practical Chemo- and Stereoselective Hydrogenation of Ketones. , 2001, Angewandte Chemie.

[13]  K. Achiwa,et al.  Versatile Chiral Bidentate Ligands Derived from α-Amino Acids: Synthetic Applications and Mechanistic Considerations in the Palladium-Mediated Asymmetric Allylic Substitutions , 2000 .

[14]  H. Wan,et al.  New chiral catalysts for reduction of ketones. , 2000, Chirality.

[15]  A. Börner,et al.  Synthesis of Heterofunctionalized Multidentate Diphosphines , 2000 .

[16]  T. Morimoto,et al.  A new class of C2-symmetric diphosphine ligands derived from valine: remarkably diverse behavior in catalytic asymmetric transformations , 1999 .

[17]  G. Zhu,et al.  NEW CHIRAL LIGANDS FOR CATALYTIC ASYMMETRIC TRANSFER HYDROGENATION OF KETONES , 1997 .

[18]  M. T. Bautista,et al.  New dihydrogen complexes: the synthesis and spectroscopic properties of iron(II), ruthenium(II), and osmium(II) complexes containing the meso-tetraphos-1 ligand , 1994 .

[19]  K. Hiroi,et al.  Intra- and intermolecular palladium-catalyzed asymmetric allylations of chiral enamines , 1990 .

[20]  H. Oehme,et al.  Alkali‐Phosphorverbindungen und ihr reaktives Verhalten, LI. Synthese und Reaktionsverhalten des [β‐Amino‐äthyl]‐phenyl‐phosphins , 1967 .