(±)-3-Methyl-1,1-diphenyl-2-butyl 3-Acetamidocrotonate and its Hydrogenation Product
摘要:
Synthesis of (+/-)-3-methyl-1,1-diphenyl-2-butyl beta-acetamidobutanoate, C23H29NO3, (10), With high diastereoisomeric excess was achieved by asymmetric hydrogenation of the stereogenic title compound, C23H27NO3, (9), in which the chirality is present in the ester part. The acetamidocrotonate (9) is planar and delimits a pro-R and a pro-S face. An intramolecular hydrogen bond between the amino group and the carboxylate group is essential to ensure planarity. One of the phenyl rings of the ester hinders one face. The hydrogenation occurs by the opposite face as proved by the crystal structure of its product of hydrogenation, (10).
Process for producing optically active 3-halogenocarboxylic acid ester and 3-azidocarboxylic acid ester
申请人:——
公开号:US20030225301A1
公开(公告)日:2003-12-04
A process for producing an optically active 3-azide-carboxylic acid ester by reacting an optically active 3-hydroxycarboxylic acid ester and a thionyl halide in the presence of a basic substance in an organic solvent to produce an optically active 3-halogenocarboxylic acid ester which is then reacted with an azide salt represented by the formula: MN
3
(wherein M is an alkaline metal) in water or a mixture of water and a water soluble organic solvent.
Enantioselective hydrogenation of β-dehydroamino acids on a cinchonidine-modified palladium catalyst
作者:Chunhui Chen、Ensheng Zhan、Yong Li、Wenjie Shen
DOI:10.1016/j.molcata.2013.08.004
日期:2013.11
Enantioselective hydrogenation of (Z)-β-dehydroamino acids on a cinchonidine-modified Pd/Al2O3 catalyst was explored. Comparative studies by using (Z)-β-dehydroamino acids and esters identified that the carboxylic group in dehydroamino acids was essentially important to get enantioselectivities (33% for aryl substituted and 46% for alkyl substituted β-dehydroaminoacids). This result extended the range
探索了在辛可尼定改性的Pd / Al 2 O 3催化剂上(Z)-β-脱氢氨基酸的对映选择性氢化。通过使用(Z)-β-脱氢氨基酸和酯进行的比较研究表明,脱氢氨基酸中的羧基对于获得对映选择性至关重要(芳基取代的33%,烷基取代的β-脱氢氨基酸46%)。该结果扩展了手性改性的Pd催化剂上α,β-不饱和羧酸的对映选择性氢化的范围,为合成旋光性β-氨基酸提供了一种新方法。
Chiral Oxo- and Oxy-Functionalized Diphosphane Ligands Derived from Camphor for Rhodium(I)-Catalyzed Enantioselective Hydrogenation
作者:Igor V. Komarov、Axel Monsees、Anke Spannenberg、Wolfgang Baumann、Ute Schmidt、Christine Fischer、Armin Börner
diphosphane 17, was performed starting from (R)-camphor. The new diphosphanes were used as ligands in the enantioselective rhodium(I)-catalyzed hydrogenation of functionalized olefins − α- and β-dehydroamino acids and their esters − in order to elucidate the effect of the oxo- and oxy-functional groups. The enantioselectivities, ranging from 2−90% ee, and the rates were strongly dependent on the type and relative
[DE] HYDROXYDIPHOSPHINE UND DEREN VERWENDUNG IN DER KATALYSE<br/>[EN] HYDROXY DIPHOSPHINES AND THEIR USE IN CATALYSIS<br/>[FR] HYDROXYDIPHOSPHINES ET LEUR UTILISATION EN CATALYSE
申请人:DEGUSSA
公开号:WO2003099832A1
公开(公告)日:2003-12-04
Die Erfindung betrifft neue unsymmetrische chirale Hydroxydiphosphine und deren Derivate der allgemeinen Formel (I), sowie deren Verwendung als Katalysatoren, insbesondere für enantioselektive Synthesen.
METHOD FOR PRODUCING OPTICALLY ACTIVE 3-AMINOCARBOXYLIC ACID ESTERS
申请人:Jaekel Christoph
公开号:US20090299089A1
公开(公告)日:2009-12-03
The invention relates to a method for producing optically active 3-aminocarboxylic acid ester compounds. According to said method, an enantiomer mixture of a mono-N-acylated 3-aminocarboxylic acid ester, which mixture was previously enriched in an enantiomer, is subjected to deacylation and then to a further enantiomer enrichment by crystallization by adding an acidic salt-forming substance.