Direct α-Chalcogenation of Aliphatic Carboxylic Acid Equivalents
作者:Aniket Gupta、Ajijur Rahaman、Sukalyan Bhadra
DOI:10.1021/acs.orglett.9b02424
日期:2019.8.2
A novel approach to α-chalcogenation of aliphaticcarboxylicacids has been developed by means of transforming them as the corresponding benzazoles. The catalyst system, consisting of CuI, DMSO, and a base, operates through a unique mechanism to access a range of practically significant thio- and selenoethers that are otherwise challenging to achieve. The applicative potentials have been exemplified
通过将脂肪族羧酸转化为相应的苯唑类,开发了一种将脂肪族羧酸进行 α-硫属元素化的新方法。由 Cu I 、DMSO 和碱组成的催化剂体系通过独特的机制运行,以获取一系列具有实际意义的硫醚和硒醚,否则这些化合物难以实现。应用潜力已通过利用所得硫属化合物作为合成生物学相关分子和合成中间体的前体来举例说明。
Elemental Sulfur-Promoted Oxidative Rearranging Coupling between o-Aminophenols and Ketones: A Synthesis of 2-Alkyl benzoxazoles under Mild Conditions
作者:Thanh Binh Nguyen、Pascal Retailleau
DOI:10.1021/acs.orglett.7b01775
日期:2017.7.21
In the presence of N-methylpiperidine, elemental sulfur was found to act as excellent oxidant in promoting oxidative rearranging coupling between o-aminophenols and ketones. A wide range of 2-alkylbenzoxazoles was obtained under mild conditions.
Elemental sulfur mediated synthesis of benzoxazoles, benzothiazoles and quinoxalines via decarboxylative coupling of 2-hydroxy/mercapto/amino-anilines with cinnamic acids
An easy and practical method has been developed for the synthesis of 2-benzylbenzoxazoles and 2-benzylbenzothiazoles using sulfur mediated decarboxylativecoupling of cinnamic acids with 2-hydroxyanilines and 2-mercaptoanilines respectively under metal- and solvent-free conditions. However, the reaction of 2-aminoanilines with cinnamic acids leads to the formation of 2-arylquinoxalines under the same
One-Pot Synthesis of 2-Substituted Benzoxazoles Directly from Carboxylic Acids
作者:Dinesh Kumar、Santosh Rudrawar、Asit K. Chakraborti
DOI:10.1071/ch08193
日期:——
Methanesulfonic acid has been found to be a highly effective catalyst for a convenient and one-pot synthesis of 2-substituted benzoxazoles by the reaction of 2-aminophenol with acid chlorides, generated in situ fromcarboxylicacids. Aryl, heteroaryl, and arylalkyl carboxylicacids provided excellent yields of the corresponding benzoxazoles. The reaction conditions were compatible with various substituents
A catalytic system comprised of Pd(OAc)2 and bidentate ligand dppe enabled first direct arylations with moisture-stable aryl sulfamates as electrophiles, and proved applicable to unprecedented C−H bond functionalizations with easily accessible alkenyl phosphates as well as benzyl phosphates.