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.
Rhodium-catalyzed synthesis of unsymmetrical di(aryl/heteroaryl)methanes using aryl/heteroarylmethyl ketones via CO–C bond cleavage
作者:Guangzhe Li、Mieko Arisawa、Masahiko Yamaguchi
DOI:10.1039/c4cc00816b
日期:——
RhH(PPh3)4 and 1,2-bis(diphenylphosphino)benzene catalyze the reaction of aryl/heteroarylmethyl ketones and arylheteroaryl ethers giving unsymmetrical diarylmethanes containing one or two heteroarenes in high yields. The reaction does not use alkali metal bases, and therefore does not form large amounts of metal waste.
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