Homogeneous catalytic hydrogenation olefinic ketones

Activation of Molecular Hydrogen by Homogeneous Catalysts S. W. Weller and G. A. Mills Catalytic Syntheses of Ketones V. I. Komarewsky and J. R. Coley Polymerization of Olefins from Cracked Gases... 

Asymmetric synthesis (i) has gained new momentum with the potential k use of homogeneous catalysts. The use of a transition metal complex with chiral ligands to catalyze a synthesis asymmetrically from a prochiral substrate is beneficial in that resolution of a normally obtained racemate product may be avoided. In certain catalytic hydrogenations of olefinic bonds, optical purities approaching 100% have been attained (2,3,4,5) hydrogenations of ketones (6,... 

Homogeneous catalytic asymmetric hydrogenation has become one of the most efficient methods for the synthesis of chiral alcohols, amines, a and (3-amino acids, and many other important chiral intermediates. Specifically, catalytic asymmetric hydrogenation methods developed by Professor Ryoji Noyori are highly selective and efficient processes for the preparation of a wide variety of chiral alcohols and chiral a-amino acids.3 The transformation utilizes molecular hydrogen, BINAP (2,2 -bis(diphenylphosphino)-l,l -binaphthyl) ligand and ruthenium(II) or rhodium(I) transition metal to reduce prochiral ketones 1 or olefins 2 to their corresponding alcohols 3 or alkanes 4, respectively.4... 

Hydrogenation is now the most utilized homogeneous catalytic reaction in process chemistry for the synthesis of enantioenriched material. The scope of highly enantioselective hydrogenation is spectacular. It ranges from olefins and ketones functionalized with ligating substituents to unfunctionalized alkenes and ketones. Examples of the asymmetric... 

Asymmetric Transfer Hydrogenation of Ketones. The first reports on asymmetric transfer hydrogenation (ATH) reactions catalyzed by chiral metallic compounds were published at the end of the seventies. Prochiral ketones were reduced using alcohols as the hydrogen source, and Ru (274,275) or Ir (276) complexes were used as catalysts. Since then, many chiral catalytic systems for homogeneous ATH of ketones, imines, and olefins have been developed (37,38,256,257,277-289). The catalytic systems are usually based on ruthenium, rhodium, or iridium, and the ATH of aryl ketones is by far the most studied. Because of the reversibility of this reaction, at high conversions, a gradual erosion of the ee of the product has been frequently reported. An azeotropic 5 2 mixture of formic acid/triethylamine can be used to overcome this limitation. 

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