Homogeneous asymmetric hydrogenation

Good reviews of asymmetric homogeneous hydrogenation catalysts and their syntheses are those of Caplar et al. 28) and Vineyard et al. (106). 

J. D. Morrison u. W. F. Master, Asymmetric Homogenous Hydrogenation, Advances in Catalysis, Vol. XXV,... 

Only a few other cobalt complexes of the type covered in this review (and therefore excluding, for example, the cobalt carbonyls) have been reported to act as catalysts for homogeneous hydrogenation. The complex Co(DMG)2 will catalyze the hydrogenation of benzil (PhCOCOPh) to benzoin (PhCHOHCOPh). When this reaction is carried out in the presence of quinine, the product shows optical activity. The degree of optical purity varies with the nature of the solvent and reaches a maximum of 61.5% in benzene. It was concluded that asymmetric synthesis occurred via the formation of an organocobalt complex in which quinine was coordinated in the trans position (133). Both Co(DMG)2 and cobalamin-cobalt(II) in methanol will catalyze the following reductive methylations ... 

I. M. Thommen, Homogeneous asymmetric hydrogenation Mature and fit for early stage drug development. Specialty Chemicals Magazine, May (2005). Hans-Ulrich Blaser, Felix Spindler and Marc Thommen, Industrial Applications m Handbook of Homogeneous Hydrogenation, (ed. J.G. de Vries and C. J. Elsevier), Wiley, (2007). 

Following Wilkinson s discovery of [RhCl(PPh3)3] as an homogeneous hydrogenation catalyst for unhindered alkenes [14b, 35], and the development of methods to prepare chiral phosphines by Mislow [36] and Horner [37], Knowles [38] and Horner [15, 39] each showed that, with the use of optically active tertiary phosphines as ligands in complexes of rhodium, the enantioselective asymmetric hydrogenation of prochiral C=C double bonds is possible (Scheme 1.8). 

Chaloner, P.A., Esteruelas, M.A., Joo, F., Oro, L.A., Homogeneous Hydrogenation, Kluwer, Dordrecht, 1994 Noyori, R., Asymmetric Catalysis in Organic Synthesis (especially Chapter 2), John Wiley Sons, Inc., New York, 1994 Ojima, I. (Ed.), Catalytic Asymmetric Synthesis,... 

Keywords Asymmetric Hydrogenation m Carbon Dioxide m Carbonylation m Dimethylformamide Enantioselectivity m Formic Acid m Homogeneous Hydrogenation n Palladium Catalysts Radical Reactions m Ruthenium Catalysts m Supercritical Fluids m Solvent Replacement... 

As recently recognized by the Nobel Chemistry award committee, the conceptualization, development, and commercial application of enantioselective, homogeneous hydrogenation of alkenes represents a landmark achievement in modem chemistry. Further elaboration of asymmetric hydrogenation catalysts by Noyori, Burk, and others has created a robust and technologically important set of catalytic asymmetric synthetic techniques. As frequently occurs in science, these new technologies have spawned new areas of fundamental research. Soon after the development of... 

The Stereochemistry of Hydrogenation of , -Unsaturated Ketones Robert L. Augustine Asymmetric Homogeneous Hydrogenation J. D. Morrison, W. F. Masler, and M. K. Neuberg... 

Such diene complexes can be used to prepare homogeneous hydrogenation catalysts in situ, especially where a variable tertiary phosphine/rhodium ratio is required3 or where an asymmetric tertiary phosphine is employed for asymmetric synthesis.4 The cyclooctadiene complex is also the starting point for the preparation a number of complexes of the type [Rh(l, 5-C8H12)L2]+ (L represents a variety of P— and N— donor ligands) of interest in homogeneous catalysis.s... 

A new family of chiral ligands for asymmetric homogeneous hydrogenation has been developed. The performance of mono- and bis-rhodium complexes of these chiral ferrocene tetraphosphine ligands in the hydrogenation of model substrates was surveyed in comparison to their ferrocene bis-phosphine analogs. 

Weis, M., Waloch, C., Seiche, W. and Breit, B. (2006) Self-assembly of bidentate ligands for combinatorial homogeneous catalysis Asymmetric rhodium-catalyzed hydrogenation. J. Am. Chem. Soc.. 128. 4188-4189. 

A simple method for the hydrosolubilization of chiral diphosphines is the introduction of a functional group such as sulfonate. Such chiral-sulfonated diphosphines can be used to prepare homogeneous hydrogenation catalysts in situ for the asymmetric reduction of prochiral substrates.1... 

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