Chiral bisphospholane ligands (Me-ketalphos): synthesis of their Rh(I) complexes and applications in asymmetric hydrogenation
作者:Qian Dai、Chun-Jiang Wang、Xumu Zhang
DOI:10.1016/j.tet.2005.10.047
日期:2006.1
Rhodium complexes of functionalized bisphospholane ligands (S,S,S,S-Me-ketalphos) 1 and (R,S,S,R-Me-ketalphos) 2 have been used as catalyst precursors for the asymmetrichydrogenation of several different types of functionalized olefins and have achieved high enantioselectivities.
GABA and L-glutamic acid analogs for antiseizure treatment
申请人:——
公开号:US20030225161A1
公开(公告)日:2003-12-04
A compound of the formula
1
wherein R
1
is a straight or branched alkyl group having from 1 to 6 carbon atoms, phenyl, or cycloalkyl having from 3 to 6 carbon atoms; R
2
is hydrogen or methyl; and R
3
is hydrogen, methyl or carboxyl; which is useful in the treatment of seizure disorders. Processes are disclosed for the preparation of the compound. Intermediates prepared during the synthesis of the compound are also disclosed.
式中的化合物
1
其中 R
1
是具有 1 至 6 个碳原子的直链或支链烷基、苯基或具有 3 至 6 个碳原子的环烷基; R
2
是氢或甲基;以及 R
3
是氢、甲基或羧基;可用于治疗癫痫发作性疾病。公开了制备该化合物的工艺。还公开了在合成该化合物过程中制备的中间体。
A facile chemoenzymatic approach to chiral non-racemic β-alkyl-γ-amino acids and 2-alkylsuccinic acids. A concise synthesis of (S)-(+)-Pregabalin
Both enantiomerically pure antipodes of GABA analogues were prepared as hydrochloride salts, by enzymatic kinetic resolution of their precursors ethyl 2-(nitromethyl)alkanoates. These latter compounds can be easily transformed into enantiomerically pure 2-alkylsuccinic acids by a Nef reaction followed by oxidation. Interestingly, this reaction was particularly easy for the neopentyl derivative (S)-(+)-7d, which underwent conversion into its corresponding succinic acid derivative (S)-(-)-8d in buffered solution. The absolute configurations of the main Compounds of interest involved are given, together with their CD spectra. (C) 2008 Elsevier Ltd. All rights reserved.
GABA AND L-GLUTAMIC ACID ANALOGS FOR ANTISEIZURE TREATMENT