is commercially available, is a practical and useful Lewis acidcatalyst for acylation of alcohols with acidanhydrides or the esterification of alcohols by carboxylic acids in the presence of p-nitrobenzoic anhydrides. The remarkably high catalytic activity of scandium triflate can be used for assisting the acylation by acidanhydrides of not only primary alcohols but also sterically-hindered secondary
Brønsted Acid Mediated Nucleophilic Functionalization of Amides through Stable Amide C−N Bond Cleavage; One‐Step Synthesis of 2‐Substituted Benzothiazoles
作者:Srabani Maity、Arnab Roy、Surajit Duari、Subrata Biswas、Asma M. Elsharif、Srijit Biswas
DOI:10.1002/ejoc.202100645
日期:2021.7.7
A TFA mediated general and simple synthetic protocol to directly cleave stable amide C−N bonds by a variety of alcohol and amine nucleophiles has been developed. Natural alcohols such as menthol and cholesterol took part in the reaction under the present reaction conditions to generate the desired esters. Structurally important 2-substituted benzothiazole derivatives have been synthesized in one pot
Cobalt‐Catalyzed Direct Aminocarbonylation of Ethers: Efficient Access to α‐Amide Substituted Ether Derivatives
作者:Le‐Cheng Wang、Bo Chen、Xiao‐Feng Wu
DOI:10.1002/anie.202203797
日期:2022.6.7
A novel cobalt-catalyzed carbonylative coupling of ethers with amines to construct α-carbonylated ethers has been achieved. Alfuzosin, a medicine for treatment of benign prostatic hyperplasia (BPH), can be synthesized by this process straightforwardly.
Mild Amide Synthesis Using Nitrobenzene under Neutral Conditions
作者:Ni Xiong、Yuanqi Dong、Bin Xu、Yang Li、Rong Zeng
DOI:10.1021/acs.orglett.2c01743
日期:2022.7.8
Amide synthesis is one of the most important transformations in organic chemistry due to the broad application in pharmaceutical drugs and organic materials. In this report, we describe a mild protocol for amide formation using the readily available nitroarenes as nitrogen sources and an inexpensive iron complex as a catalyst. Because of the use of the pH-neutral conditions and the avoidance of the
由于在药物和有机材料中的广泛应用,酰胺合成是有机化学中最重要的转化之一。在本报告中,我们描述了一种温和的酰胺形成方案,使用现成的硝基芳烃作为氮源和廉价的铁络合物作为催化剂。由于使用 pH 中性条件和避免强氧化剂或还原剂,可以很好地耐受各种芳香族和脂肪族醛以及具有各种官能团的硝基芳烃。在详细研究的基础上提出了一种合理的机制,其中铁催化剂引发自由基过程,溶剂作为 O 原子受体起关键作用。
Visible‐Light Enabled Dehydroxylative Alkylation of α‐Hydroxy Carboxylic Acid Derivatives via C−O Bond Cleavage
Existing protocols for the boryl radical promoted dehydroxylative alkylation of α-hydroxy carboxylic acidderivatives via C−O bond cleavage require the use of expensive radical initiators and relatively harsh conditions. An improved protocol is presented that uses cheap and readily available sodium tetraphenyl borate (NaBPh4) as a boron radical source. The reaction using the photoredox catalytic system