Synthesis and Pharmacological Evaluation of 1-Alkyl-N-[(1R)-1-(4-fluorophenyl)-2-methylpropyl]piperidine-4-carboxamide Derivatives as Novel Antihypertensive Agents
established, asymmetric hydrogenation of challenging tetrasubstituted α,β‐unsaturatedcarboxylicacids is rarely reported. We demonstrate enantioselective hydrogenation of cyclic and acyclic tetrasubstituted α,β‐unsaturatedcarboxylicacids via cobalt(II) catalysis. This protocol showed broad substrate scope and gave chiral carboxylicacids in good yields with excellent enantiocontrol (up to 98 % yield and
Tetrahydronaphthalene derivatives for improving short-term memory
申请人:Hoffmann-La Roche Inc.
公开号:US05120759A1
公开(公告)日:1992-06-09
Novel compounds of the formula ##STR1## wherein R.sup.1 is lower-alkyl, lower-alkoxy-lower-alkyl, lower-alkylthio-lower-alkyl or furyl, R.sup.2 is lower-alkyl, phenyl-lower-alkyl or cyclohexyl-lower-alkyl, each of R.sup.3 and R.sup.6 independently is hydrogen or fluorine, each of R.sup.4 and R.sup.5 independently is hydrogen or lower-alkoxy or together are methylenedioxy, ethylenedioxy or ethylenoxy and n is an integer from 1 to 3, have a pronounced activity in counteracting cerebral insufficiency or improving cognitive functions and also reduce the multiple-resistance towards cytostatics in the treatment of tumors or of chloroquine resistance in the treatment of malaria. They can accordingly be used as medicaments, especially for the control or prevention of cerebral insufficiency or for the improvement of cognitive functions. The novel compounds of formula I can be manufactured by O-acylating a likewise novel compound of the formula ##STR2## wherein R.sup.2 is lower-alkyl, phenyl-lower-alkyl or cyclohexyl-lower-alkyl, each of R.sup.3 and R.sup.6 independently is hydrogen or fluorine, each of R.sup.4 and R.sup.5 independently is hydrogen or lower-alkoxy or together are methylenedioxy, ethylendioxy or ethylenoxy and n is an integer from 1 to 3.
Cobalt-Catalyzed Asymmetric Hydrogenation of α,β-Unsaturated Carboxylic Acids by Homolytic H<sub>2</sub> Cleavage
作者:Hongyu Zhong、Michael Shevlin、Paul J. Chirik
DOI:10.1021/jacs.9b13876
日期:2020.3.18
The asymmetrichydrogenation of α, β-unsaturatedcarboxylicacids using readily prepared bis(phosphine) cobalt(0) 1,5-cyclooctadiene precatalysts is described. Di-, tri- and tetra-substituted acrylic acid derivatives with various substitution patterns as well as dehydro-α-amino acid derivatives were hydrogenated with high yields and enantioselectivities, affording chiral carboxylicacids including
Synthesis of New Water-Soluble Atropisomeric Ligands Derived from the MeOBIPHEP Skeleton: Applications for Asymmetric CH Bond Formation and Mechanistic Studies
We have extended the methodology developed for the preparation of atropisomeric chiral ligandsderivedfrom the MeOBIPHEPligand to water-soluble ones. The hydrophilic ligands bearing sodium carboxylate and methylammonium chloride moieties were easily synthesized under mild conditions in a short sequence and in high yields. Their solubility and acid/base properties were also determined. The ruthenium(II)
我们将为制备从MeOBIPHEP配体衍生的阻转异构手性配体而开发的方法扩展至水溶性。带有羧酸钠和甲基氯化铵部分的亲水配体很容易在温和条件下以短序列和高收率合成。还确定了它们的溶解度和酸/碱性质。含有4-CO 2 Na-和3,5-(CO 2 Na)2取代的MeOBIPHEP类似物的钌(II)催化剂表现出出色的活性,并得到了衣康酸二甲酯和2-(4- ee s≥92%的氟苯基)-3-甲基巴豆酸。D 2中后一种底物的不对称氢化研究O作为溶剂提供了对该机理的认识。
Tetrasulfonated diphosphine compounds and metal complexes thereof for
申请人:Hoffmann-La Roche Inc.
公开号:US05536858A1
公开(公告)日:1996-07-16
The invention is concerned with novel water-soluble racemic or optically active compounds of formulae ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently signify lower alkyl or lower alkoxy; m and n are 0, 1 or 2; and X signifies hydrogen, an alkali :metal, the equivalent of an earth alkali metal or an ammonium ion; with the provision that R.sup.3 is in position 4 or 5 and R.sup.4 is in position 4' or 5'. The invention is also concerned with complexes of such compounds with a metal of Group VIII. These complexes are, useful as catalysts for asymmetric hydrogenation and for enantioselective hydrogen displacement in prochiral allylic systems.