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
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
A visible-light-induced trifluoromethylalkynylation of 1,6-dialkenes was developed under transition-metal-free and photocatalyst-free conditions, enabling the construction of three C–C bonds in a single preparation step.