标题：Divergent synthesis of chiral cyclic azides via asymmetric cycloaddition reactions of vinyl azides
作者：Thirupathi, Nuligonda; Wei, Fang; Tung, Chen-Ho; Xu, Zhenghu
作者机构：[Thirupathi, Nuligonda; Wei, Fang; Tung, Chen-Ho; Xu, Zhenghu] Shandong Univ, Sch Chem & Chem Engn, Key Lab Colloid & Interface Chem, Minist Educ, 27 更多
通讯作者：Xu, ZH;Xu, ZH
通讯作者地址：[Xu, ZH]Shandong Univ, Sch Chem & Chem Engn, Key Lab Colloid & Interface Chem, Minist Educ, 27 South Shanda Rd, Jinan 250100, Shandong, Peoples R Chin 更多
摘要：Vinyl azides, bearing conjugated azide and alkene functional groups, have been recognized as versatile building blocks in organic synthesis. In general vinyl azides act as 3-atom (CCN) synthons through the fast release of molecular nitrogen and have been extensively utilized in the construction of structurally diverse N-heterocycles. Keeping the azide moiety intact in organic transformations to synthesis chiral azides is an important but challenging task. Herein, we report an enantioselective copper(II)/BOX-catalyzed cycloaddition of vinyl azides, generating diverse chiral cyclic azides. alpha-Aryl substituted vinyl azides react with unsaturated keto esters through an inverse-electron-demand hetero-Diels-Alder reaction to afford chiral azido dihydropyrans with excellent enatioselectivities. In contrast, cyclohexenyl azides undergo a diastereo- and enantio-selective Diels-Alder reaction giving important azido octahydronaphthalenes with three continuous stereogenic centers. Notable features of these reactions include a very broad scope, mild reaction conditions and 100% atom economy.