On enantioselective separation of phenoxypropionates using permethylated β-cyclodextrin HPLC and GC columns
摘要:
Investigations on chiral phenoxypropionates using permethylated beta-cyclodextrin HPLC and GC columns showed a decrease in enantioselective separation efficiency from mecoprop-methyl and dichlorprop-methyl to the threefold chlorinated fenoprop-methyl. This corresponded to decreasing electron density in the aromatic system due to the increasing negative inductive effect of 3 chlorine substituents. Investigation on methyl-(RS)2-(2,4-dichloro-3,6-dinitrophenoxy)-propionate confirmed the influence of electrophilic substituents while determination of ethyl-(RS)-2-methoxypropionate emphasized the necessity of an aromatic system for enantioselective separation on beta-cyclodextrin stationary phases. For fenoprop-methyl as well as for the aryloxyphenoxypropionates diclofop-methyl and fluazifop-butyl, reversed phase HPLC showed higher separation performance than high resolution capillary GC. (C) 1997 Elsevier Science Ltd.
[EN] PROSTACYCLIN DERIVATIVES<br/>[FR] DÉRIVÉS DE PROSTACYCLINE
申请人:CONCERT PHARMACEUTICALS INC
公开号:WO2011003058A1
公开(公告)日:2011-01-06
This invention relates to novel prostacyclin derivatives and acceptable salts thereof. The invention also provides compositions comprising a compound of this invention and the use of such compositions in methods of treating diseases and conditions beneficially treated by prostacyclin, and in particular those diseases and conditions beneficially treated by dilators of systemic and pulmonary arterial vascular beds or by platelet aggregation inhibitors.
Phosphane ligands with two binding sites of differing hardness for enantioselective Grignard cross coupling
作者:Andreas Terfort、Henri Brunner
DOI:10.1039/p19960001467
日期:——
A series of new, chiral phosphanes is presented, individual members of which were designed to serve as ligands in transition-metal mediated asymmetric Grignard cross coupling reactions. These ligands are characterized by a side chain containing one or two oxygen atoms with the capacity to act as binding sites for the incoming Grignard reagent. A number of structural parameters for the compounds was varied to learn about the reaction mechanism. Most of the ligands were tested in two cross coupling reactions, the formation of 3-phenylbut-1-ene and of 2,2′-dimethyl-1,1′-binaphthyl, respectively. Although both systems gave modest enantiomeric excesses it was not possible to make a comparison of their respective abilities.
Enantioselective cyclopropane syntheses using the chiral carbene complexes (SFe)- and (RFe)-C5H5(CO)(PR3)Fe:CHCH3+. A mechanistic analysis of the carbene transfer reaction
作者:Maurice Brookhart、Yumin Liu、Emma W. Goldman、Debra A. Timmers、Gregory D. Williams
DOI:10.1021/ja00003a028
日期:1991.1
ethylidene transfer from these complexes to styrene, vinylacetate, and isopropenyl acetate gave methylcyclopropanes in high optical yields. A mechanistic analysis of the transferreaction is presented by using the stereochemical results obtained coupled with deuterium labeling and relative reactivity studies. It is concluded that the most likely mechanism for carbene transferinvolvesreaction of the
通过使用标准技术将对映体纯的酰基配合物转化为相应的对映体纯的卡宾配合物(S Fe )-和(R Fe )-C 5 H 5 (CO)(PR 3 )Fe=CHCH 3 + 。对映选择性亚乙基从这些配合物转移到苯乙烯、乙酸乙烯酯和乙酸异丙烯酯,得到高光学产率的甲基环丙烷。通过使用获得的立体化学结果以及氘标记和相对反应性研究,对转移反应进行了机理分析。得出的结论是,卡宾转移的最可能机制涉及烯烃与 C 5 H 5 (CO)(PR 3 )Fe=CHCH 3 + 的次要但更具反应性的向斜异构体的反应,然后是发展中的亲电子中心的背面攻击在 Fe-Cα 键上的 Cγ。
PROSTACYCLIN DERIVATIVES
申请人:Masse Craig E.
公开号:US20120270934A1
公开(公告)日:2012-10-25
This invention relates to novel prostacyclin derivatives and acceptable salts thereof. The invention also provides compositions comprising a compound of this invention and the use of such compositions in methods of treating diseases and conditions beneficially treated by prostacyclin, and in particular those diseases and conditions beneficially treated by dilators of systemic and pulmonary arterial vascular beds or by platelet aggregation inhibitors.