描述了炔基(苯基)碘化甲苯磺酸盐与全氟烷烃亚磺酸钠(R fn SO 2 Na)的无添加剂和过渡金属的全氟烷烃磺酰化。亲核性差的R fn SO 2 Na与二氯甲烷中的炔基(苯基)碘鎓盐在室温下在氮气氛下反应5-60分钟,从而以令人满意的定量收率提供了各种炔属三氟甲酮和炔基全氟烷基砜。碘鎓盐中芳基乙炔基部分的苯环上取代基的位置对反应有很大影响。五元环乙烯基砜的形成表明该反应通过亚烷基卡宾中间体。此外,成功扩大反应规模也证明了该新方法的实用性。该方法的优点包括反应时间短,条件温和以及易于获得全氟链烷磺酰化试剂(R fn SO 2 Na)。
Radical alkynyltrifluoromethylation of alkenes with actylenic triflones has been achieved. This radical chain reaction is initiated by a catalytic amount of an electron-donor–acceptor complex composed of Togni’s reagent and N-methylmorpholine. This transformation proceeds under exceptionally mild and operationally simple conditions. A variety of alkenes are compatible in this protocol including aliphatic
Herein, we developed a copper‐catalyzed approach for the remote C(sp3)−H alkynylation of N‐fluoro‐sulfonamides. With Cu(OTf)2 as the catalyst, the carbon radical which generated from nitrogen radical‐mediated 1,5‐hydrogen atom transfer, go through an addition/fragmentation reaction with various acetylene sulfones. A variety of internal alkynes were synthesized in high yield and regioselectivity. Notably
1,1,2‐Trifunctionalization of Terminal Alkynes by Radical Addition–Translocation–Cyclization–Trapping for the Construction of Highly Substituted Cyclopentanes
作者:Youqing Yang、Constantin G. Daniliuc、Armido Studer
DOI:10.1002/anie.202011785
日期:2021.1.25
Radical 1,1,2‐trifunctionalization of terminal alkynes by an addition–translocation–cyclization–trapping sequence using readily available alkynyl triflones as trifluoromethyl radical precursors and trapping reagents is reported. Cascades occur by addition of the trifluoromethyl radical to a terminal alkyne, 1,5‐hydrogen atom transfer, 5‐exo‐cyclization, and subsequent alkynylation to provide (1‐tr
Rhodium(III)-catalyzed [3+2] annulative coupling between oximes and electron-deficient alkynes
作者:Xukai Zhou、Songjie Yu、Zisong Qi、Xingwei Li
DOI:10.1007/s11426-015-5408-8
日期:2015.8
Rhodium(III)-catalyzedcoupling between ketoximes and alkynes via C-H activation and annulation typically followed the [4+2] selectivity to afford isoquinolines. By designing alkynes bearing a highly electron-withdrawing group and under substrate control, we have successfully switched the selectivity of the coupling between oximes and alkynes to the alternative [3+2] annulation, leading to the efficient
A method for remote radical C–H alkynylation at unactivated sites is reported. C–Hfunctionalization proceeds via 1,5-hydrogen atom transfer (HAT) to amidyl radicals that are generated via an addition/fragmentation reaction. The readily installed N-allylsulfonyl moiety is used as a precursor of the N-centered radical. Unactivated secondary and tertiary as well as selected primary C–H bonds can be functionalized