Enantioselective Construction of Cyclobutanes: A New and Concise Approach to the Total Synthesis of (+)-Piperarborenine B
作者:Jiang-Lin Hu、Liang-Wen Feng、Lijia Wang、Zuowei Xie、Yong Tang、Xiaoge Li
DOI:10.1021/jacs.6b08279
日期:2016.10.12
and multisubstituted alkenes was developed to furnish optically active cyclobutanes in high yields with >99/1 dr and up to >99% ee. By application of the newly developed method, the totalsynthesis of (+)-piperarborenine B was completed in eight steps from methylidenemalonate and olefin in 17% overall yield with >99/1 dr and 99% ee.
开发了一种高度非对映选择性和对映选择性 Cu(II)/SaBOX 催化的 [2+2] 环加成亚甲基丙二酸酯和多取代烯烃,以高产率提供光学活性环丁烷,产率 >99/1 dr 和高达 >99% ee。通过应用新开发的方法,从亚甲基丙二酸酯和烯烃分八步完成了 (+)-哌醋甲酯 B 的全合成,总产率为 17%,>99/1 dr 和 99% ee。
Ring-Opening Reactions of Donor–Acceptor Cyclobutanes with Electron-Rich Arenes, Thiols, and Selenols
作者:Alexander Kreft、Stephanie Ehlers、Peter G. Jones、Daniel B. Werz
DOI:10.1021/acs.orglett.9b02197
日期:2019.8.16
Donor–acceptor (D–A) cyclobutanes with two geminal ester groups as acceptors are reacted with electron-rich arenes as nucleophiles to afford ring-opened products. AlCl3 mediates this Friedel–Crafts-type reaction. A variety of donors and electron-rich arenes are used. Nucleophilic thiols and selenols also trigger this ring-opening reaction. Furthermore, a comparison of various physical parameters has
Diastereoselective [3 + 2] Cycloaddition of Quinoxalin-2(1<i>H</i>)-ones with Donor–Acceptor Cyclopropanes: Efficient Synthesis of Tetrahydro pyrrolo[1,2-<i>a</i>]quinoxalin-4(5<i>H</i>)-ones
heterocycles like benzoxazinone, isoquinoxalinone, and dibenzoxazepine derivatives were also suitable for the desired annulation reaction. The current method is applicable for the scale-up reaction. Further, the utility of this annulation reaction is demonstrated by the synthesis of densely functionalized proline derivatives.
Synthesis of 2-Unsubstituted Pyrrolidines and Piperidines from Donor–Acceptor Cyclopropanes and Cyclobutanes: 1,3,5-Triazinanes as Surrogates for Formylimines
作者:Lennart K. B. Garve、Alexander Kreft、Peter G. Jones、Daniel B. Werz
DOI:10.1021/acs.joc.7b01631
日期:2017.9.1
A synthetic procedure to access 2-unsubstituted pyrrolidines and piperidines is presented. In the presence of MgI2 as Lewis acid, donor–acceptor cyclopropanes or corresponding cyclobutanes were treated with 1,3,5-triazinanes, leading to the five- or six-membered ring systems under mild conditions in yields up to 93%. This protocol tolerates a great variety of functional groups and thus provides an