Superoxide dismutase mimetics. Part 2: synthesis and structure–Activity relationship of glyoxylate- and glyoxamide-Derived metalloporphyrins
摘要:
Novel glyoxylate- and glyoxamide-derived metalloporphyrins 26-58 were synthesized and evaluated as potential superoxide dismutase (SOD) mimetics. Relative to previously studied MnTBAP analogues, the glyoxylate-derived metalloporphyrins 32, 39, and 54 and glyoxamide-derived metalloporphyrin 49, exhibited enhanced activity in the SOD assay and the majority of the analogues in the current series showed enhanced inhibition of lipid peroxidation and catalase activity. (C) 2003 Elsevier Science Ltd. All rights reserved.
Hydroquinone derivatives useful in the production of vitamin E
申请人:Hoffmann-La Roche Inc.
公开号:US04689427A1
公开(公告)日:1987-08-25
The present invention is directed to novel hydroquinone derivatives which are useful as intermediates for the manufacture of (R,R,R)-.alpha.-tocopherol (natural vitamin E) as well as of racemic .alpha.-tocopherol. The invention is also directed to a process for the preparation of the hydroquinone derivatives of the invention.
There is described a novel process for producing hydroquinone derivatives of the formula ##STR1## wherein R is an ether protecting group, and their conversion into d-.alpha.-tocopherol, starting from compounds of the formula ##STR2## wherein R is an ether protecting group and R.sup.1 is hydrogen or an ether protecting group.
Process for the manufacture of optically active compounds
申请人:Hoffmann-La Roche Inc.
公开号:US04582919A1
公开(公告)日:1986-04-15
There is described a novel process for producing hydroquinone derivatives of the formula ##STR1## wherein R is an ether protecting group, and their conversion into d-.alpha.-tocopherol, starting from compounds of the formula ##STR2## wherein R is an ether protecting group and R.sup.1 is hydrogen or an ether protecting group.
Single‐Site Molybdenum Catalyst for the Synthesis of Fumarate
作者:Huifang Jiang、Rui Lu、Xiaoqin Si、Xiaolin Luo、Jie Xu、Fang Lu
DOI:10.1002/cctc.201900332
日期:2019.9.5
pyridine nitrogen and oxygen in hydroxyl of 8‐hydroxyquinoline coordinated with Mo atom. The crystal catalyst was stabilized by π‐π stacking interaction and hydrogen bonds to form isolated Mo specie. The single‐site molybdenumcatalyst exhibited excellent catalytic performance in didehydroxylation reactions with highselectively of dibutyl fumarate (86 %) product at mild reaction condition. Deuterium isotopic
Zn(OTf)<sub>2</sub>-Promoted Chemoselective Esterification of Hydroxyl Group Bearing Carboxylic Acids
作者:Narsimha Mamidi、Debasis Manna
DOI:10.1021/jo302502r
日期:2013.3.15
Selective esterification of aliphatic and aromatic carboxylic acids with various alcohols is studied using triphenylphosphine, I-2, and a catalytic amount of Zn(OTf)(2). Use of this catalyst allows the formation of esters at a faster rate with good to excellent yield by activating the in situ generated acyloxyphosphonium ion intermediate. During the esterification process, both their aromatic and aliphatic hydroxyl groups are fully preserved from trans-esterification. The results show that the bulkiness and the reactivity of this doubly activated intermediate III control the selectivity and the rate of the reaction, respectively. The method is also useful for direct amidation reactions.