An efficient synthesis of 2,5-disubstitutedoxazolesvia Co(III) catalysis is described herein. The synthesis is achieved under mild conditions through [3+2] cycloaddition of N-pivaloyloxyamides and alkynes. The reaction operates through an internal oxidation pathway and features a very broad substrate scope. The one-step synthesis of natural products such as texamine and balsoxin has been demonstrated
Formation of Acyl-Substituted Nitrile Ylides by Rh<sub>2</sub>(OAc)<sub>4</sub>-Catalyzed Decomposition of<i>α</i>-Diazocarbonyl Compounds in Nitriles
作者:Kazuaki Fukushima、Toshikazu Ibata
DOI:10.1246/bcsj.68.3469
日期:1995.12
The Rh2(OAc)4-catalyzed reactions of α-diazocarbonyl compounds in nitrile in the presence of dimethyl acetylenedicarboxylate (DMAD) gave oxazole and pyrrole derivatives. The formation of the oxazole derivatives is explained in terms of the 1,5-cyclization of an acyl-substituted nitrileylide intermediate, and the formation of the pyrrole derivatives is explained by the 1,3-dipolar cycloaddition of
A practicalone‐pot protocol for the synthesis of 2,5‐disubstitutedoxazoles from 1‐aryl‐2‐nitroethanones was reported. In the presence of iron/AcOH in acetonitrile, the reaction of 1‐aryl‐2‐nitroethanones with trimethyl orthoacetate or trimethyl orthobenzoate delivered the corresponding 2,5‐disubstitutedoxazoles in moderate to good yields.
Formation and Reaction of Acyl Substituted Nitrile Ylide through the Rh<sub>2</sub>(OAc)<sub>4</sub>-Catalyzed Reaction of α-Diazocarbonyl Compounds with Benzonitrile
作者:Toshikazu Ibata、Kazuaki Fukushima
DOI:10.1246/cl.1992.2197
日期:1992.11
The rhodium(II) acetate-catalyzedreaction of α-diazocarbonyl compounds with benzonitrile and dimethyl acetylenedicarboxylate gave oxazoles and pyrrole-3,4-dicarboxylates through the 1,5-cyclizatio...
Divergent Conversion of <i>N</i>-Acyl-isoxazol-5(2<i>H</i>)-ones to Oxazoles and 1,3-Oxazin-6-ones Using Photoredox Catalysis
作者:Mingjing Mei、Devireddy Anand、Lei Zhou
DOI:10.1021/acs.orglett.9b00903
日期:2019.5.17
visible light photoredox catalysis has been disclosed. The catalyst-controlled divergent mechanisms, namely the oxidative and reductive quenching catalytic cycle, are utilized. Various oxazoles and 1,3-oxazin-6-ones are selectively obtained from the same isoxazol-5-one skeleton under mild conditions.