The invention provides compounds formulae I-III, their preparation, and their use as pharmaceutically active immunosuppressive agents for the treatment of autoimmune disorders, organ transplant rejection, disorders associated with an activated immune system, as well as other disorders modulated by lymphopenia or SIP receptors.
P-fluorobenzoyl chloride for characterization of active hydrogen functional groups by fluorine-19 nuclear magnetic resonance spectrometry
作者:M. P. Spratt、H. C. Dorn
DOI:10.1021/ac00276a014
日期:1984.10.1
Direct Synthesis of Esters from Alkylarenes and Carboxylic Acids: The C–H Bond Dehydroesterification
作者:Jin Zhang、Jianghan Cao、Jiabin Zhou、Jie Zhang、Yinglin Zhao、Zhida Zhang、Renhua Liu
DOI:10.1021/acs.joc.3c00752
日期:2023.7.7
directly esterified by carboxylic acids to produce benzyl esters in high yields is reported. This reaction is catalyzed by Pd nanoparticles (NPs) on N-doped carbon (CN) composites based on a carbonizing Al-MIL-101(NH2) material, and no oxidants or hydrogen acceptors are required. Use of o-alkylbenzoic acids as substrates leads to phthalides, whereas with carboxylic acids and alkylarenes as the feedstock
在此,报道了烷基芳烃的苄基C-H键被羧酸直接酯化以高产率生产苄基酯的反应。该反应由基于碳化Al-MIL-101(NH 2 )材料的N掺杂碳(CN)复合材料上的Pd纳米颗粒(NP)催化,并且不需要氧化剂或氢受体。使用o-烷基苯甲酸作为底物产生苯并呋喃酮,而以羧酸和烷基芳烃作为原料,反应产生苄基酯。这些使用容易获得的烷基芳烃代替卤化苄或苯甲醇作为原料一步合成苄基酯而无需氧化剂的反应本质上是原子效率和步骤效率的。制备了 CN 复合材料和 CN 负载的 Pd NP 催化剂,并对其进行了良好的表征。所提出的机制涉及羧基和苄基的脱氢,以及通过有机钯中间体从苄基中夺氢,将苄基的 C-H 键转化为 C-O 键。动力学同位素效应 ( k H / k D= 2.77) 表明烷烃芳烃的 C(sp 3 )–H 键断裂是速率决定步骤。
Atom-economic and stereoselective catalytic synthesis of fully substituted enol esters/carbonates of amides in acyclic systems enabled by boron Lewis acid catalysis
strategy for enol ester synthesis. However, the reported examples come with limitations, including the utilization of noble metal catalysts, the control of regio- and Z/E selectivity, and an application in the synthesis of enol carbonates. Herein, a boron Lewis acid-catalyzed intermolecular carboacyloxylation of ynamides with esters to access fully substituted acyclic enol esters in high yield with