Divergent Reactivity of Nitrocyclopropanes with Huisgen Zwitterions and Facile Syntheses of 3-Alkoxy Pyrazolines and Pyrazoles
作者:Changjiang Yang、Wei Liu、Zijian He、Zhengjie He
DOI:10.1021/acs.orglett.6b02415
日期:2016.10.7
A novel annulation reaction of trans-2-substituted-3-nitrocyclopropane-1,1-carboxylates with in situ generated Huisgen zwitterions is reported, providing facile synthesis of 3-alkoxy pyrazolines in good yields and high diastereoselectivities. This reaction unveils the divergent reactivity of the nitrocyclopropanes as a kind of versatile donor–acceptor cyclopropanes. It is also demonstrated that the
报道了一种新的反式-2-取代-3-硝基环丙烷-1,1-羧酸盐与原位产生的惠斯根两性离子的环化反应,可轻松合成3-烷氧基吡唑啉,产率高且非对映选择性高。该反应揭示了硝基环丙烷作为一种多功能的供体-受体环丙烷具有不同的反应性。还证明了由偶氮二羧酸二叔丁酯制备的3-烷氧基吡唑啉可以容易地以中等收率转化成相应的3-烷氧基1 H-吡唑。