Chemoselective Acylation of Primary Amines and Amides with Potassium Acyltrifluoroborates under Acidic Conditions
作者:Alberto Osuna Gálvez、Cédric P. Schaack、Hidetoshi Noda、Jeffrey W. Bode
DOI:10.1021/jacs.7b00059
日期:2017.2.8
proceeds rapidly in water. The reaction is fast at acidic pH and tolerates alcohols, carboxylic acids, and even secondary amines in the substrates. It is applicable to the functionalization of primary amides, sulfonamides, and other N-functional groups that typically resist classical acylations and can be applied to late-stage functionalizations.
当前用于构建酰胺键的方法通过脱水偶联过程将胺和羧酸连接起来,该过程通常需要有机溶剂、昂贵且通常危险的偶联试剂,并掩盖其他官能团。在这里,我们描述了使用伯胺和酰基三氟硼酸钾的酰胺形成,由在水中快速进行的简单氯化剂促进。该反应在酸性 pH 值下很快,并且可以耐受底物中的醇、羧酸,甚至仲胺。它适用于伯酰胺、磺酰胺和其他通常抵抗经典酰化的 N 官能团的官能化,并可应用于后期官能化。
Synthesis of α-Amidoketones through the Cascade Reaction of Carboxylic Acids with Vinyl Azides under Catalyst-Free Conditions
作者:Cai Gao、Qianting Zhou、Li Yang、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.joc.0c01871
日期:2020.11.6
An efficient synthesis of α-amidoketone derivatives through the cascade reactions of carboxylicacids with vinyl azides is presented. Compared with literature protocols, notable features of this new method include catalyst-free conditions, broad substrate scope, good tolerance of a wide range of functional groups, and high efficiency. In addition, the synthetic potential of this method as a tool for
A series of 2,5-disubstituted 4-oxazoleacetic acid derivatives was synthesized and evaluated for hypolipidemicactivity. Among them, those with a thienyl group at C-5 of the oxazole ring exerted highly potent hypolipidemic effects in rats. 2-(4-Fluorophenyl)-5-(3-thienyl)-4-oxazoleacetic acid (88) was the most potent derivative: it was about 2 times as active in normal SD male rats and about 4 times
Synthesis of secondary and tertiary amides without coupling agents from amines and potassium acyltrifluoroborates (KATs)
作者:Anne Schuhmacher、Tomoya Shiro、Sarah J. Ryan、Jeffrey W. Bode
DOI:10.1039/d0sc01330g
日期:——
Although highly effective for most amide syntheses, the activation of carboxylicacids requires the use of problematic coupling reagents and is often poorly suited for challenging cases such as N-methyl amino acids. As an alternative to both secondary and tertiary amides, we report their convenient synthesis by the rapid oxidation of trifluoroborate iminiums (TIMs). TIMs are easily prepared by acid-promoted
general and highly efficient method for the synthesis of dl-2,3-diamide-1,4-diones via autoxidative dehydrogenative homocoupling of N-acyl-2-aminoacetophenones mediated by t-BuOK. The transformation is mild, operationally simple, and environmentally friendly. Control experiments and stereochemical results suggest that the substrate undergoes autoxidation followed by a diastereoselective SN2 reactopm.
我们在此报告了一种通用且高效的方法,用于通过由t -BuOK 介导的N-酰基-2-氨基苯乙酮的自氧化脱氢同源偶联来合成dl -2,3-diamide-1,4- diones。改造温和、操作简单、环保。对照实验和立体化学结果表明,底物发生自氧化,然后发生非对映选择性 S N 2 反应。