Generation of Diazomethyl Radicals by Hydrogen Atom Abstraction and Their Cycloaddition with Alkenes
作者:Yong‐Liang Su、Kuiyong Dong、Haifeng Zheng、Michael P. Doyle
DOI:10.1002/anie.202105472
日期:2021.8.16
pyrazolines from α-diazo compounds and conjugated alkenes is reported. The direct hydrogen atom transfer (HAT) process of α-diazo compounds promoted by the tert-butylperoxy radical generates electrophilic diazomethyl radicals, thereby reversing the reactivity of the carbon atom attached with the diazo group. The regiocontrolled addition of diazomethyl radicals to carbon-carbon double bonds followed by intramolecular
报道了从 α-重氮化合物和共轭烯烃合成吡唑啉的通用催化方法。叔促进α-重氮化合物的直接氢原子转移(HAT)过程-丁基过氧自由基产生亲电重氮甲基自由基,从而逆转与重氮基团相连的碳原子的反应性。重氮甲基自由基在碳-碳双键上的区域控制加成,然后在末端重氮氮上进行分子内闭环和互变异构化,以良好的收率和出色的区域选择性提供了多种吡唑啉。该策略克服了α-重氮化合物与烯烃的传统偶极[3+2]-环加成中缺电子烯烃的局限性。此外,重氮甲基自由基的直接形成提供了umpolung反应性,从而为重氮化合物的多功能转化开辟了新的机会。