Niobium-promoted reaction of α-phenylglyoxylic acid with ortho-functionalized anilines: synthesis of 2-arylbenzothiazoles and 3-aryl-2H-benzo[b][1,4]benzoxazin-2-ones
作者:Filipe Penteado、Marcelo M. Vieira、Gelson Perin、Diego Alves、Raquel G. Jacob、Claudio Santi、Eder J. Lenardão
DOI:10.1039/c6gc02495e
日期:——
A new and general method to prepare 2-arylbenzothiazoles and 3-aryl-2H-benzo[b][1,4]benzoxazin-2-ones by the reaction of -arylglyoxylic acid with o-aminothiophenol and o-aminophenol respectively is described. The use of ammonium niobium oxalate (ANO)...
Oxone-mediated oxidative carbon-heteroatom bond cleavage: synthesis of benzoxazinones from benzoxazoles with α-oxocarboxylic acids
作者:Hua Wang、Hua Yang、Yiping Li、Xin-Hua Duan
DOI:10.1039/c3ra47660j
日期:——
A metal-free oxidative cleavage of benzoxazoles using Oxone as an oxidant has been developed. The in situ formed o-aminophenol has been proved to react successfully with α-oxocarboxylic acids affording the benzoxazinones in moderate to good yields.
the synthesis of quinazolinones, quinoxalinones, benzooxazinones, and benzothiazoles from the reactions of α-keto acids with 2-aminobenzamides, benzene-1,2-diamines, 2-aminophenols, and 2-aminobenzenethiols, respectively, is described. The reactions were conducted under catalyst-free conditions, using water as the sole solvent with no additive required, and successfully applied to the synthesis of sildenafil
Unexpected TFA-catalyzed tandem reaction of benzo[d]oxazoles with 2-oxo-2-arylacetic acids: synthesis of 3-aryl-2H-benzo[b][1,4]oxazin-2-ones and cephalandole A
TFA-catalyzed reaction of benzo[d]oxazoles with 2-oxo-2-arylacetic acids: synthesis of 3-aryl-2H-benzo[b][1,4]oxazin-2-ones and the natural product cephalandole A.
The development of biomimetic chemistry based on the NAD(P)H with hydrogen gas as terminal reductant is a long‐standing challenge. Through rational design of the chiral and regenerable NAD(P)H analogues based on planar‐chiral ferrocene, a biomimetic asymmetric reduction has been realized using bench‐stable Lewis acids as transfer catalysts. A broad set of alkenes and imines could be reduced with up