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
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
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。
Remote Site-Specific Radical Alkynylation of Unactivated C–H Bonds
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
Diversity‐Oriented Desulfonylative Functionalization of Alkyl Allyl Sulfones
作者:Yong Xia、Armido Studer
DOI:10.1002/anie.201903668
日期:2019.7.15
The diversity‐oriented desulfonylative functionalization of alkyl allyl sulfones with various sulfone‐type reagents by radical chemistry has been developed. The readily installed allylsulfonyl moiety acts as a C‐radical precursor, which is substituted by various functionalities using sulfur‐based radical trapping reagents. The generality of this approach is documented by the successful desulfonylative