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Diastereoselective Hydrogenation (diastereoselective + hydrogenation)
Selected AbstractsDiastereoselective Hydrogenation of Substituted Quinolines to Enantiomerically Pure DecahydroquinolinesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010Maja Heitbaum Abstract The stereoselective hydrogenation of auxiliary-substituted quinolines was used to build up saturated and partially saturated heterocycles. In a first step, the formation and diastereoselective hydrogenation of 2-oxazolidinone-substituted quinolines to 5,6,7,8-tetrahydroquinolines is reported. In this unprecedented process, stereocenters on the carbocyclic quinoline ring were formed with a dr of up to 89:11. Platinum oxide as a catalyst and trifluoroacetic acid as a solvent were found to be optimal for high levels of chemo- and stereoselectivity in this step. In a second hydrogenation step, the completely saturated decahydroquinolines with 4 newly formed stereocenters were obtained with enantioselectivities of up to 99%. Rhodium on carbon as a catalyst and acetic acid as a solvent gave the best results for this hydrogenation and allowed a traceless cleavage of the chiral auxiliary. Thus, this new method allows an efficient stereoselective synthesis of valuable 5,6,7,8-tetrahydro- and decahydroquinoline products. [source] Rhodium-Catalyzed Enantioselective and Diastereoselective Hydrogenation of ,-Ketoenamides: Efficient Access to anti 1,3-Amino Alcohols,ANGEWANDTE CHEMIE, Issue 33 2009Huiling Geng Nützliche chirale Bausteine werden mit ausgezeichneter Enantio- und Diastereoselektivität bei einer Tandemhydrierung von (Z)-,-Ketoenamiden gebildet, die wiederum durch direkte Kondensation von 1,3-Diketonen mit Acetamid erhalten werden (siehe Schema). Die chiralen Aminoalkoholprodukte können durch Hydrogenolyse mit Pd/C in nützliche ,-Arylisobutylamine überführt werden. R1=Aryl, Heteroaryl, Methyl; R2=Alkyl. [source] ChemInform Abstract: Rhodium-Catalyzed Enantioselective and Diastereoselective Hydrogenation of ,-Ketoenamides: Efficient Access to anti 1,3-Amino AlcoholsCHEMINFORM, Issue 51 2009Huiling Geng Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Mixtures of Chiral Phosphorous Acid Diesters and Achiral P Ligands in the Enantio- and Diastereoselective Hydrogenation of Ketimines.CHEMINFORM, Issue 40 2007Manfred T. Reetz Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Enantio- and Diastereoselective Hydrogenation via Dynamic Kinetic Resolution by a Cationic Iridium Complex in the Synthesis of ,-Hydroxy-,-amino Acid Esters.CHEMINFORM, Issue 3 2007Kazuishi Makino Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Diastereoselective Hydrogenation of Substituted Quinolines to Enantiomerically Pure DecahydroquinolinesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010Maja Heitbaum Abstract The stereoselective hydrogenation of auxiliary-substituted quinolines was used to build up saturated and partially saturated heterocycles. In a first step, the formation and diastereoselective hydrogenation of 2-oxazolidinone-substituted quinolines to 5,6,7,8-tetrahydroquinolines is reported. In this unprecedented process, stereocenters on the carbocyclic quinoline ring were formed with a dr of up to 89:11. Platinum oxide as a catalyst and trifluoroacetic acid as a solvent were found to be optimal for high levels of chemo- and stereoselectivity in this step. In a second hydrogenation step, the completely saturated decahydroquinolines with 4 newly formed stereocenters were obtained with enantioselectivities of up to 99%. Rhodium on carbon as a catalyst and acetic acid as a solvent gave the best results for this hydrogenation and allowed a traceless cleavage of the chiral auxiliary. Thus, this new method allows an efficient stereoselective synthesis of valuable 5,6,7,8-tetrahydro- and decahydroquinoline products. [source] | ||||||||||