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Efficient Stereoselective Synthesis (efficient + stereoselective_synthesis)
Selected AbstractsA Rapid and Efficient Stereoselective Synthesis of (Z)- and (E)-Allyl Bromides from Baylis,Hillman Adducts Using Bromo(dimethyl)sulfonium Bromide,HELVETICA CHIMICA ACTA, Issue 7 2006Biswanath Das Abstract Treatment of Baylis,Hillman adducts 1 with bromo(dimethyl)sulfonium bromide, Br(Me2)S+Br,, in MeCN was found to stereoselectively afford (Z)- and (E)-allyl bromides 2. The reaction is rapid at room temperature, high-yielding, and highly stereoselective. [source] Efficient Stereoselective Synthesis of Nitrocyclopropanes by the Oxidative Cyclization of Michael Adducts of Nitroolefins with Activated Methylene CompoundsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2008Renhua Fan Abstract An efficient oxidative cyclopropanation of the Michael adducts of nitroolefins with activated methylene compounds by the combination of iodobenzene diacetate and tetrabutylammonium iodide is reported. Highly functionalized nitrocyclopropanes are synthesized in moderate to good yields via the Michael addition and cyclopropanation with high diastereoselectivity and enantioselectivity under mild conditions. [source] ChemInform Abstract: A New Mild Base-Catalyzed Mannich Reaction of Hetero-Arylamines in Water: Highly Efficient Stereoselective Synthesis of ,-Aminoketones under Microwave Heating.CHEMINFORM, Issue 33 2009Wen-Juan Hao 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] ChemInform Abstract: An Efficient Stereoselective Synthesis of 1-Iodo- or 1-Phenyl Selenenyl-2-aryl-3-azabicyclo[3.1.0]hexane via Electrophilic Cyclization of Benzyl-2-arylmethylidenecyclopropylmethyl-amines.CHEMINFORM, Issue 18 2008Weijun Fu 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] An Efficient Stereoselective Synthesis of Substituted 1,3-Dienes.CHEMINFORM, Issue 19 2005Kyungsoo Oh Abstract For Abstract see ChemInform Abstract in Full Text. [source] An Efficient Stereoselective Synthesis of (E)-,-Fluoroalkenyliodonium Salts.CHEMINFORM, Issue 16 2005Masanori Yoshida Abstract For Abstract see ChemInform Abstract in Full Text. [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] | ||||||||||