Substrate Activity Screening: A Fragment-Based Method for the Rapid Identification of Nonpeptidic Protease Inhibitors
作者:Warren J. L. Wood、Andrew W. Patterson、Hiroyuki Tsuruoka、Rishi K. Jain、Jonathan A. Ellman
DOI:10.1021/ja0547230
日期:2005.11.1
A new fragment-basedmethod for the rapid development of novel and distinct classes of nonpeptidic protease inhibitors, SubstrateActivityScreening (SAS), is described. This method consists of three steps: (1) a library of N-acyl aminocoumarins with diverse, low molecular weight N-acyl groups is screened to identify protease substrates using a simple fluorescence-based assay, (2) the identified N-acyl
A novel, efficient, and metal-free dual C–O bond formation reaction for the synthesis of carboxylic anhydrides from aryl aldehydes via cross-dehydrogenative coupling is described. Heating a mixture of aromatic aldehydes and an aqueous solution of tert-butyl hydroperoxide as oxidant in the presence of catalytic nBu4PBr in chlorobenzene at 80 °C for 3 h afforded the corresponding carboxylic anhydrides
描述了一种新颖,有效且无金属的双C-O键形成反应,用于通过交叉脱氢偶联由芳基醛合成羧酸酐。在催化性n Bu 4 PBr在氯苯中的存在下,于80°C加热芳香族醛和氢过氧化叔丁基水溶液作为氧化剂,在80°C下加热3 h,得到相应的羧酸酐,收率良好至优异。
Characterization of methyl glycosides at the pico- to nano-gram level
Abstract We describe a general method that permits characterization of 100-pg to 1-ng quantities of sugars. Thus, oligosaccharides are subjected to methanolysis, followed by per- p -bromobenzoylation or pernaphthoylation, and the methylglycoside peresters are separated by high-pressure liquid chromatography. The method is also applicable to amino and acetamido sugars. If required, the separated sugar
Sunlight assisted direct amide formation via a charge-transfer complex
作者:Irit Cohen、Abhaya K. Mishra、Galit Parvari、Rachel Edrei、Mauricio Dantus、Yoav Eichen、Alex M. Szpilman
DOI:10.1039/c7cc05300b
日期:——
We report on the use of charge-transfercomplexes between amines and carbon tetrachloride, as novel way to activate the amine for photochemical reactions. This principle is demonstrated in a mild, transition metal free, visible light assisted, dealkylative amide formation from feedstock carboxylic acids and amines. The low absorption coefficient of the complex allows deep light penetration and thus
high yields within 5–10 min. However, for nitro-substituted derivatives, unexpectedly, N,N-diethylamides were isolated without anhydride formation. These results indicated the pronounced effect of substituents in governing these potential side reactions which can significantly affect the yields of acylation reactions promoted by phosphonium species.
研究了由磷介导的羧酸活化作用形成酸酐。在各种体系下,取决于试剂的反应性,在碱的存在下苯甲酸的活化导致苯甲酸酐以不同的速率形成。使用Ph 3 P–I 2 / Et 3 N组合,大多数芳酸在5–10分钟内即可高产率转化为相应的酸酐。然而,对于硝基取代的衍生物,出乎意料的是,N,N分离了-二乙酰胺而没有酸酐形成。这些结果表明取代基在控制这些潜在的副反应中具有显着的作用,其可显着影响由phospho物种促进的酰化反应的产率。