在过量化学计量的活化试剂和/或过渡金属催化剂的存在下,转酰胺基反应通常由反应性底物介导。在这里,我们报告了使用 CO 2作为无痕催化剂:在催化量的 CO 2存在下,使用伯、仲和叔酰胺供体加速转酰胺反应。包括氨基酸衍生物在内的各种胺类亲核试剂都被耐受,这表明转酰胺基在肽修饰和聚合物降解中的实用性(例如,Nylon-6,6)。特别是,N , O -二甲基羟基酰胺(Weinreb 酰胺)在 CO 2催化的转酰胺基反应中与 N 2相比表现出明显的反应性大气层。进行了比较 Hammett 研究和动力学分析,以阐明分子 CO 2的催化活化机制,这得到了 DFT 计算的支持。我们将CO 2在转酰胺基反应中的积极作用归因于通过与亲电子CO 2共价结合来稳定四面体中间体。
Multifunctional transformation of amide C–N bond cleavage is reported. The protocol applies to benzamide, thioamide, alcohols, and mercaptan under similar reaction conditions catalyzed by NaOTs. It is noteworthy that NaOTs can not only be recycled and reused for up to three cycles without significant loss in catalytic activity, but also catalyze gram-grade reactions. This study provides a novel solution
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。
Oxidative Amidation of Aldehydes and Alcohols with Primary Amines Catalyzed by KI-TBHP
作者:K. Rajender Reddy、C. Uma Maheswari、M. Venkateshwar、M. Lakshmi Kantam
Photoinduced C(sp<sup>3</sup>)–H chlorination of amides with tetrabutyl ammonium chloride
作者:Yanshuo Zhu、Wei Yu
DOI:10.1039/d1ob02081a
日期:——
developed for the site-selective C(sp3)–H chlorination of amides with tetrabutyl ammonium chloride as the chlorinating agent. The reaction features a tandem sequence that involves a (diacetoxyiodo)benzene-mediated and chloride anion-involved N–H chlorination followed by photoinitiated chlorineatom transfer. A wide variety of carboxamides and sulfonamides were chlorinated at the δ-position by using this method
<scp>
Silver‐Mediated
<i>N</i>
‐Trifluoromethylation
</scp>
of Amides and Peptides
作者:Zhenzhen Zhang、Jiayan He、Lin Zhu、Haiwen Xiao、Yewen Fang、Chaozhong Li
DOI:10.1002/cjoc.202000132
日期:2020.9
products in satisfactory yields. The protocol is also applicable to amino acid derivatives, resulting in efficient and chemoselective N‐trifluoromethylation of di‐ and tri‐peptides with retention of configuration. A mechanism involving reductiveelimination of Ag(III) intermediates to form N—CF3 bonds is proposed.