Tandem Aza Michael Addition–Vinylogous Nitroaldol Condensation: Construction of Highly Substituted <i>N</i>-Fused 3-Nitropyrazolopyridines
作者:Owk Obulesu、V. Murugesh、Battu Harish、Surisetti Suresh
DOI:10.1021/acs.joc.8b00746
日期:2018.6.15
A base-mediated tandem aza-Michael addition–vinylogous nitroaldol condensation has been described between 3,5-dialkyl 4-nitropyrazoles and alkynyl ketones/aldehydes. This transition metal-free atom economical transformation occurred via C–N and C═C bond formations in one step with the elimination of water. The construction of a variety of highly substituted N-fused 3-nitropyrazolopyridine derivatives
3,5-二烷基4-硝基吡唑与炔基酮/醛之间存在碱介导的串联氮杂-迈克尔加成-乙烯基硝基醛缩合反应。这种无过渡金属的原子经济转变是通过消除水和一步形成C–N和C═C键而实现的。已经证明以高收率构建了多种高度取代的N-稠合的3-硝基吡唑并吡啶衍生物。用不对称取代的4-硝基吡唑已经实现了良好到优异的区域选择性。