Copper-Catalyzed Trifluoromethylalkynylation of Isocyanides
摘要:
The title reaction proceeds with acetylenic triflones and isocyanides under mild conditions using copper as a catalyst. This transformation provides an efficient access to (E)-N-alkyl trifluoromethyl alkynyl ketoimines, which are useful building blocks for the synthesis of CF3-containing N-heterocycles, propargylamines, etc.
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)。
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
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
The regioselectivesynthesis of pyrazole triflones has been achieved by 1,3-dipolar cycloaddition of triflyl alkynes and hydrazonoyl chloride in the presence of Hünig’s base. Pyrazolo[5,1-a]isoquinoline triflones were also regioselectively synthesized for the first time via tandem 1,3-dipolar cycloaddition/oxidative aromatization between triflyl alkynes and C,N-cyclic azomethine imines.
在Hünig碱的存在下,通过三氟乙炔和酰氯的1,3-偶极环加成反应可实现吡唑三氟酮的区域选择性合成。吡唑并[5,1- a ]异喹啉三氟甲磺酸还通过三氟乙炔与C,N-环偶氮甲亚胺之间的串联1,3-偶极环加成/氧化芳构化而首次区域选择性合成。
Radical 1,2,3-tricarbofunctionalization of α-vinyl-β-ketoesters enabled by a carbon shift from an all-carbon quaternary center
作者:Qi Zhang、Mong-Feng Chiou、Changqing Ye、Xiaobin Yuan、Yajun Li、Hongli Bao
DOI:10.1039/d2sc00902a
日期:——
enables further C–Cbondformation on the tertiary carbon intermediate with the aim of reconstructing a new all-carbon quaternary center. The good functional group compatibility ensures diverse synthetic transformations of this method. Experimental and theoretical studies reveal that the excellent diastereoselectivity should be attributed to the hydrogen bonding between the substrates and solvent.