Nanostructured ruthenium on γ-Al2O3 catalysts for the efficient hydrogenation of aromatic compounds
摘要:
Free and trioctylamine (TOA)-stabilized ruthenium nanoparticles have been prepared by decomposition of the metal precursor Ru(eta(6)-cycloocta-1,3,5-diene)(eta(4)-cycloocta-1,5-diene) under mild conditions (room temperature, hydrogen atmospheric pressure). The nanoparticles have been deposited on gamma-Al2O3 supports having different surface area. The resulting systems are active in the hydrogenation of methyl benzoate to methyl cyclohexanoate with a reaction rate decreasing in the order Ru(TOA)/gamma-Al-2 O-3 (high surface area, catalyst D) > Ru(TOA)/gamma-AI(2)O(3) (Catalyst C) > Ru/gamma-Al2O3 (high surface area, catalyst B) > Ru/gamma-Al2O3 (catalyst A). Catalysts A-D are long lived and can be reused without loss of activity; they are considerably more active than a commercial ruthenium on gamma-Al2O3 sample. High Resolution Transmission Electron Microscopy analyses of such systems show that the nanoparticles are homogeneously dispersed on the support and that the size distribution decreases in the order catalyst A, 2.9 nm > catalyst B. 2.8 nm > catalyst C, 2.4 nm > catalyst D, 2.3 nm. Based on the easy hydrogenation of the aromatic ring to the cyclohexane derivative, an efficient synthesis of 4-carbomethoxyformylcyclohexane, important starting material in the preparation of pharmaceutical products, from the largely available methyl 4-formylbenzoate, has been set up in the presence of catalyst D. (C) 2003 Elsevier B.V. All rights reserved.
A Bifunctional Copper Catalyst Enables Ester Reduction with H<sub>2</sub>: Expanding the Reactivity Space of Nucleophilic Copper Hydrides
作者:Birte M. Zimmermann、Trung Tran Ngoc、Dimitrios-Ioannis Tzaras、Trinadh Kaicharla、Johannes F. Teichert
DOI:10.1021/jacs.1c09626
日期:2021.10.13
activation of esters through hydrogen bonding and formation of nucleophilic copper(I) hydrides from H2, resulting in a catalytic hydride transfer to esters. The reduction step is further facilitated by a proton shuttle mediated by the guanidinium subunit. This bifunctional approach to ester reductions for the first time shifts the reactivity of generally considered “soft” copper(I) hydrides to previously
采用基于铜 (I)/NHC 配合物和胍有机催化剂的双功能催化剂,促进了以 H 2作为末端还原剂的催化酯还原成醇。这里采用的方法能够通过氢键同时活化酯,并从 H 2形成亲核的氢化铜 (I) ,从而导致氢化物催化转移到酯。由胍亚基介导的质子穿梭进一步促进了还原步骤。这种酯还原的双功能方法首次将通常认为的“软”氢化铜 (I) 的反应性转变为以前不反应的“硬”酯亲电子试剂,并为用催化剂和 H 2替代化学计量还原剂铺平了道路.
FIBROSIS INHIBITOR
申请人:Sumitomo Pharmaceuticals Company, Limited
公开号:EP1479384A1
公开(公告)日:2004-11-24
Medicament being useful as a fibrosis inhibitor for organs or tissues, which comprises a compound of the formula (I):
wherein Ring Z is optionally substituted pyrrole ring, etc.; W2 is -CO-, -SO2-, optionally substituted C1-C4 alkylene, etc.; Ar2 is optionally substituted aryl, etc.; W1 and Ar1 mean the following (1) and (2):
(1) W1 is optionally substituted C1-C4 alkylene, etc.; Ar1 is optionally substituted bicyclic heteroaryl having 1 to 4 nitrogen atoms as ring-forming atoms:
(2) W1 is optionally substituted C2-C5 alkylene, optionally substituted C2-C5 alkenylene, etc.; and
Ar1 is aryl or monocyclic heteroaryl, which is substituted by carboxyl, alkoxycarbonyl, etc. at the ortho- or meta-position thereof with respect to the binding position of W1,
or a pharmaceutically acceptable salt thereof.
Mesoporous poly-melamine-formaldehyde (mPMF) – a highly efficient catalyst for chemoselective acetalization of aldehydes
作者:Mei Xuan Tan、Liuqun Gu、Nannan Li、Jackie Y. Ying、Yugen Zhang
DOI:10.1039/c3gc40297e
日期:——
A mesoporous poly-melamine-formaldehyde polymer with a high surface area, good porosity and a high density of amine and triazine functional groups was investigated as a highly efficient hydrogen-bonding catalyst. This porousorganicpolymer was found to be highly effective in catalyzing chemoselective acetalization of aldehydes, without the consumption of any dehydrating agents. The turnover frequency
[EN] A METHOD OF ACETALIZING AN ALDEHYDE<br/>[FR] PROCÉDÉ D'ACÉTALISATION D'UN ALDÉHYDE
申请人:AGENCY SCIENCE TECH & RES
公开号:WO2013137830A1
公开(公告)日:2013-09-19
A method of acetalizing an aldehyde comprising reacting said aldehyde with an alcohol in the presence of a polymeric catalyst to form an acetal wherein the polymeric catalyst is a mesoporous poly-melamine-formaldehyde polymer.
Medicament being useful as a fibrosis inhibitor for organs or tissues, which comprises a compound of the formula (I):
wherein Ring Z is optionally substituted pyrrole ring, etc.; W
2
is —CO—, —SO
2
—, optionally substituted C
1
-C
4
alkylene, etc.; Ar
2
is optionally substituted aryl, etc.; W
1
and Ar
1
mean the following (1) and (2):
(1) W
1
is optionally substituted C
1
-C
4
alkylene, etc.; Ar
1
is optionally substituted bicyclic heteroaryl having 1 to 4 nitrogen atoms as ring-forming atoms:
(2) W
1
is optionally substituted C
2
-C
5
alkylene, optionally substituted C
2
-C
5
alkenylene, etc.; and
Ar
1
is aryl or monocyclic heteroaryl, which is substituted by carboxyl, alkoxycarbonyl, etc. at the ortho- or meta-position thereof with respect to the binding position of W
1
, or a pharmaceutically acceptable salt thereof.