Oxidize Amines to Nitrile Oxides: One Type of Amine Oxidation and Its Application to Directly Construct Isoxazoles and Isoxazolines
作者:Xiao-Wei Zhang、Xiao-Lin He、Nan Yan、Hong-Xing Zheng、Xiang-Guo Hu
DOI:10.1021/acs.joc.0c02281
日期:2020.12.4
A facile oxidative heterocyclization of commercially available amines and tert-butyl nitrite with alkynes or alkenes leading to isoxazoles or isoxazolines is described. The unprecedented strategy of the oxidation of an amine directly to a nitrile oxide was used in this cyclization process. This reaction is highly efficient, regiospecific, operationally simple, mild, and tolerant of a variety of functional
Acyclic nitronate olefin cycloaddition (ANOC): regio- and stereospecific synthesis of isoxazolines
作者:Liang Ma、Luyao Kou、Feng Jin、Xionglve Cheng、Suyan Tao、Gangzhong Jiang、Xiaoguang Bao、Xiaobing Wan
DOI:10.1039/d0sc05607c
日期:——
We report the first demonstrations of intra- and intermolecular acyclic nitronate olefin cycloaddition (ANOC) reactions that enable the highly efficient syntheses of isoxazolines bearing various functional groups. This general approach to accessing γ-lactone fused isoxazolines was hitherto unprecedented. The room temperature transformations reported herein exhibit wide substrate scopes, as evidenced
Coupling Reaction of Cu-Based Carbene and Nitroso Radical: A Tandem Reaction To Construct Isoxazolines
作者:Rongxiang Chen、Yanwei Zhao、Shangwen Fang、Wenhao Long、Hongmei Sun、Xiaobing Wan
DOI:10.1021/acs.orglett.7b02885
日期:2017.11.3
unprecedented cross-coupling reaction between copper carbene and nitroso radical has been developed. This radical-carbene couplingreaction (RCC reaction) offers a novel approach for the preparation of various isoxazolines, which features the construction of C–C, C–O, and C═N bonds in a one-pot process. The synthetic utility of our method is further enhanced by its mild reaction conditions, wide substrate
Nitrolic acids are prepared in good yields from primary nitroalkanes or primary alkyl bromides. Upon heating in THF, they afford the corresponding nitrileoxides under neutral conditions. In the presence of dipolarophiles, isoxazoles are obtained in yields up to 95%. For the less stable alkoxycarbonyl- and arylnitrolic acids the crude nitrolic acids can be directly engaged in the cycloaddition reaction