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
An Expedient Synthesis of Alkynyl Trifluoromethyl Sulfones
作者:Michael Hanack、Bärbl Wilhelm、L. R. Subramanian
DOI:10.1055/s-1988-27646
日期:——
The hitherto difficultly attainable alkynyl trifluoromethyl sulfones 7 were prepared by the reaction of alkynyl sodium salts 6 with trifluoromethanesulfonic anhydride (1) in modest to good yields. The reactivity of 7 with different nucleophiles was studied.
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