Enantioselective synthesis organocatalysis

Specific Brpnsted acid catalysis is a popular field within the domain of asymmetric organocatalysis. Since the introduction of stronger chiral Brpnsted acids as powerful catalysts for enantioselective synthesis in 2004, numerous asymmetric Brpnsted acid-catalyzed transformations have been developed. 

Reviews on phase-transfer catalysis for the syntheses of a-amino acids, (a) Ooi, T. and Maruoka, K. (2004) Asymmetric organocatalysis of structurally well-defined chiral quaternary ammonium fluorides. Acc. Chem. Res., 37, 526-533 (b) Maruoka, K. and Ooi, T. (2003) Enantioselective amino acid synthesis by chiral phase-transfer catalysis. Chem. Rev., 103, 3013-3028 (c) Ooi, T. and Maruoka, K. (2003) Enantioselective synthesis of a-amino acids by chiral phase-transfer catalysis. Yuki Gosei Kagaku Kyokaishi (J. Synth. Org. Chem.) 61, 1195-1206. 

Hong BC, Lin CW, Liao WK, Lee GH (2013) Sequential asymmetric catalysis in Michael-Michael-Michael aldol reactions merging organocatalysis with photoredox catalysis in a one-pot enantioselective synthesis of highly functionalized decalines bearing a quaternary carbon stereocenter. Org Lett 15 6258-6261... 

Another novel extension of asymmetric organocatalysis was reported by Hintermann and Schmitz towards the successful development of an organo-catalytic enantioselective double-bond isomerisation, which has been previously associated with the field of metal catalysis. Therefore, an asymmetric synthesis of the 2,5-diphenylphosphol-2-ene fragment was achieved via the enantioselective cinchonine-catalysed double-bond isomerisation of a wc50-2,5-diphenyl-phosphol-3-ene amide into a 2,5-diphenylphosphol-2-ene amide with an enantioselectivity of up to 83% ee (Scheme 10.10). This new asymmetric concept opened the way to a catalytic enantioselective synthesis of 2,5-diarylphospho-lane building blocks for many applications in transition metal catalysis. 

The enantioselective synthesis of spirocyclic compounds has long been pursued by organic chemists. Since the advent of organocatalysis, a plethora of new... 

Selected recent developments in the area of asymmetric organocatalysis in our laboratory have been briefly summarized. Enamine catalysis, Brpnsted acid catalysis, and iminium catalysis turn out to be powerful new strategies for organic synthesis. Using Hantzsch ester as the hydride source, highly enantioselective transfer hydrogenantion reactions have been developed. We have also developed an additional new con-... 

For recent reviews, see (a) Berkessel, A. and Groger, H. (2005) Asymmetric Organocatalysis From Biomimetic Concepts to Potveiful Methods for Asymmetric Synthesis, Wiley VCH Verlag GmbH, Weinheim (b) Dalko, P.L (ed.) (2007) Enantioselective Organocatalysis Reactions and Experimental Procedures, John Wiley Sons, New York. 

The conceptual introduction of organocatalysis as a tool for organic synthesis took place relatively late in the twentieth century, but since the beginning this area of work has attracted much interest, in particular when enantioselective transformations are involved [16, 18-25]. This is not surprising as the possibility of the direct transfer of the chiral information from a simple organic molecule to an achiral substrate in a catalytic process has always been very attractive. 

Iminium organocatalysis was key to the enantioselective total synthesis of (—)-flustramine B (157) from the marine bryozoan Flustra foliacea by MacMillan and co-workers (Scheme 31) [137], which is discussed here despite not incorporating the entire C5 unit in one step. On treatment of the Boc-protected... 

Carbons and Carbon Supported Catalysts in Hydroprocessing 2 Chiral Sulfur Ligands Asymmetric Catalysis 3 Recent Developments in Asymmetric Organocatalysis 4 Catalysis in the Refining of Fischer-Tropsch Syncrude 5 Organocatalytic Enantioselective Conjugate Addition Reactions A Powerful Tool for the Stereocontrolled Synthesis of Complex Molecules... 

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