卡普拉霉素及其同系物被认为是开发治疗多重耐药 (MDR)结核分枝杆菌感染新药的重要先导分子。由于难以用生物学上感兴趣的官能团选择性地化学修饰天然产物的所需位置,因此为提高功效而对辣椒霉素进行的广泛的结构-活性关系研究受到了限制。我们通过使用源自手性(氯-4-甲氧基苯基)(氯苯基)甲醇的新保护基团,针对尿苷脲基氮和伯醇,开发了卡普拉霉素及其类似物的高效合成方法。手性非外消旋(2,6-二氯-4-甲氧基苯基)(2,4-二氯苯基)甲醇衍生物是解析外消旋-3-氨基-1,3-二氢-5-苯基-2 H ‐1的有用试剂, 4-苯二氮卓-2-酮,其( S )构型异构体在提高卡普拉霉素的杀分枝杆菌活性方面发挥着重要作用。
Ruthenium-Catalyzed Rearrangement of Aldoximes to Primary Amides in Water
作者:Rocío García-Álvarez、Alba E. Díaz-Álvarez、Javier Borge、Pascale Crochet、Victorio Cadierno
DOI:10.1021/om3006917
日期:2012.9.10
The rearrangement of aldoximes to primaryamides has been studied using the readily available arene-ruthenium(II) complex [RuCl2(η6-C6Me6)P(NMe2)3}] (5 mol %) as catalyst. Reactions proceeded cleanly in pure water at 100 °C without the assistance of any cocatalyst, affording the desired amides in high yields (70–90%) after short reaction times (1–7 h). The process was operative with both aromatic
Geometrical isomerism in the S-alkyl thiohydroximate series: a new oxime fragmentation
作者:J. H. Davies、R. H. Davis、P. Kirby
DOI:10.1039/j39680000431
日期:——
S-alkyl thiohydroximates from the results of Beckmann rearrangements on both geometricalisomers. The anti-(alkylthio)-isomers undergo fragmentation under Beckmann conditions. The syn-(alkylthio)-isomers may be converted to the anti-isomers by irradiation with u.v. light. Other evidence concerning the geometry of this series of compounds is discussed.
Selective Deoxygenation of Various N–O Bonds Catalyzed by Rhodium Carbonyl Clusters in the Presence of H<sub>2</sub>O and CO and Their Heterogenization Using Amino-Substituted Polystyrenes
amines, and 5) amine oxides to amines. The above-mentioned rhodium catalyst system was heterogenized by using amino-substituted polystyrenes. Rh6 and Rh14 carbonyl clusters of [Rh6(CO)15H]−, [Rh6(CO)15]2−, and [Rh14(CO)25]4−, were formed on the polymer surface. The characteristic features of the catalysis of the polymer-boundrhodium cluster complexes are described in relation to the corresponding homogeneous
One-Pot Copper(I)-Catalyzed Synthesis of 3,5-Disubstituted Isoxazoles
作者:Trond V. Hansen、Peng Wu、Valery V. Fokin
DOI:10.1021/jo050163b
日期:2005.9.1
3,5-Disubstituted isoxazoles are obtained in good yields by a convenient one-pot, three-step procedure utilizing a regioselective copper(I)-catalyzed cycloaddition reaction between in situ generated nitrile oxides and terminal acetylenes. Most functional groups do not interfere with the reaction, which can be performed in aqueous solvents without protection from oxygen. Since all reagents are used