Synthesis and application of peripherally alkyl-functionalized dendritic pyrphos ligands: Homogeneous-supported catalysts for enantioselective hydrogenation
摘要:
A new series of dendritic ligands with a chiral diphosphine located at the focal point have been synthesized through coupling of (R, R)-3,4-bis(biphenylphosphino)pyrrolidine (pyrphos) with peripherally alkyl-functionalized benzoic acid dendrons. These ligands were employed in the Rh-catalyzed asymmetric hydrogenation of prochiral dehydroamino acids, exhibiting excellent catalytic activities and enantioselectivities. The second-generation dendritic catalyst could be recovered by simple liquid-liquid biphasic separation and reused four times without serious loss of its activity and selectivity. (C) 2009 Elsevier B.V. All rights reserved.
Novel Chiral Dendritic Diphosphine Ligands for Rh(I)-Catalyzed Asymmetric Hydrogenation: Remarkable Structural Effects on Catalytic Properties
作者:Bing Yi、Qing-Hua Fan、Guo-Jun Deng、Yue-Ming Li、Li-Qin Qiu、Albert S. C. Chan
DOI:10.1021/ol036512a
日期:2004.4.1
series of dendritic ligands with a chiral diphosphine located at the focal point have been synthesized through coupling of pyrphos 2 with Frechet-type polyether dendron 3. The relationship between the primary structure of the dendrimer and its catalytic properties was established in the Rh-catalyzed asymmetric hydrogenation of alpha-acetamido cinnamic acid 4. A remarkable structural effect on catalytic
Facile Synthesis of Chiral Diphosphine-Containing Multiple Dendrimeric Catalysts for Enantioselective Hydrogenation
作者:Liwen Zhao、Ji Liu、Yu Feng、Yanmei He、Qinghua Fan
DOI:10.1002/cjoc.201200648
日期:2012.9
PyrPhos‐functionalized codendrimers have been synthesized via a liquid‐phase strategy in high yields. The resulting dendrimeric PyrPhos ligands were purified by a simple solvent precipitation without the need for chromatographicseparation, and well characterized by 1H, 13C and 31P NMR, MALDI‐TOF mass spectroscopy as well as elemental analysis. Their rhodiumcomplexes were applied to the asymmetric hydrogenation of
通过液相策略以高收率合成了一种新型的手性二膦PyrPhos功能化共聚酯。生成的树枝状PyrPhos配体通过简单的溶剂沉淀法纯化,无需进行色谱分离,并通过1 H,13 C和31 P NMR,MALDI-TOF质谱以及元素分析进行了很好的表征。他们的铑配合物用于α的不对称氢化乙酰胺基肉桂酸。获得了优异的对映选择性,这与使用相应的小分子催化剂的对映选择性相当。另外,这些共聚体催化剂表现出比具有位于聚(芳基醚)树突的焦点处或聚(丙烯亚胺)树状体的外围的Rh(PyrPhos)位点的树状聚合物催化剂更好的催化性能。
Verfahren zur enantioselektiven Synthese von 2(R)-Benzylbernsteinsäuremonoamid-Derivaten
申请人:HOECHST AKTIENGESELLSCHAFT
公开号:EP0512415A2
公开(公告)日:1992-11-11
Es werden zwei Verfahren zur Herstellung der optisch reinen Verbindungen der allgemeinen Formel 1 beschrieben.
wobei
R1, R2 z. B. gleich Alkyl,
R3, R4 z. B. gleich Wasserstoff und
R5 z. B. gleich Wasserstoff bedeuten.
Beide Verfahren beinhalten als Schlüsselschritte die enantioselektive Hydrierung einer C = C-Doppelbindung und die regioselektive Monoamidbildung eines Dicarbonsäurederivats.
本文介绍了制备通式 1 光学纯化合物的两种工艺。
其中
R1、R2 例如是烷基、
R3、R4 例如为氢,以及
R5 例如为氢。
这两种工艺的关键步骤是 C = C 双键的对映选择性氢化和二羧酸衍生物的区域选择性单酰胺形成。
Neue homochirale Diphosphine
申请人:HOECHST AKTIENGESELLSCHAFT
公开号:EP0512416A2
公开(公告)日:1992-11-11
Neue homochirale Diphosphine beispielsweise der Struktur (2)
wobei R z.B. für Wasserstoff oder Methyl steht,
sind geeignete Liganden für Katalysatoren für asymmetrische Hydrierungen.