Copper‐Catalyzed Alkynylation of C(sp3)−H Bonds in N‐Fluoro‐sulfonamides

Abstract Herein, we developed a copper‐catalyzed approach for the remote C( sp 3 )−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, celecoxib‐derived substrate can also gave the corresponding functionalized product in good yield under the standard conditions. magnified image