Base-induced cycloreversion of nitrile oxide cycloadducts: conversion of imines into secondary and tertiary amides and aromatic aldehydes into acids without a conventional oxidising agent
作者:R. Alan Aitken、Swati V. Raut
DOI:10.1039/p19960000747
日期:——
protonated to give secondary amides or treated in situ with alkyl halides to give tertiary amides in moderate to good overall yield, although the reaction is restricted to examples with an aromatic substituent at the 5-position. The 1,4,2-dioxazoles 15, formed by cycloaddition of benzonitrile oxide to aromatic aldehydes, similarly undergo cycloreversion allowing direct conversion either into substituted
一系列取代的Δ的2 -1,2,4-恶二唑啉(4,5-二氢-1,2,4-恶二唑)12已经制备由氧化腈的1,3-偶极环加成到亚胺并且发现,当用KOBu t处理,进行环还原,得到腈和酰胺阴离子。它们可以被质子化以得到仲酰胺,或者可以用烷基卤原位处理,以中等至良好的总收率得到叔酰胺,尽管该反应仅限于在5-位具有芳族取代基的实例。通过将苯甲腈氧化物环加成到芳族醛上而形成的1,4,2-二恶唑15类似地经历环还原,从而允许直接转化为取代的苯甲酸或它们的甲酯。