Oxidative and dehydrative cyclizations of nitroacetate esters with Mn(OAc)3
作者:Barry B Snider、Qinglin Che
DOI:10.1016/s0040-4020(02)00911-0
日期:2002.9
Reaction of α-unsubstituted nitroacetates with Mn(OAc)3 gives mixtures of isoxazolines, formed by dehydration to a nitrile oxide that undergoes cycloaddition, and isoxazoline oxides or cyclopropane, formed by oxidative cyclization. Oxidative cyclization is favored with electron-rich alkenes and cycloaddition with the nitrile oxide to give isoxazolines is favored with electron-poor alkenes. On the other
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
Catalyst-Free Formation of Nitrile Oxides and Their Further Transformations to Diverse Heterocycles
作者:Luca De Angelis、Alexandra M. Crawford、Yong-Liang Su、Daniel Wherritt、Hadi Arman、Michael P. Doyle
DOI:10.1021/acs.orglett.0c04130
日期:2021.2.5
transfer from tert-butyl nitriteundermildconditions and without the use of a catalyst or an additive is reported. This transformation is broadly applicable to the synthesis of furoxans by dimerization and isoxazoles and isoxazolines by cycloaddition. This methodology is also applied for the millimole-scale synthesis of two biologically active compounds. The formation of the nitrile oxide from a diazoacetamide