Copper-Catalyzed Direct Amidation of Heterocycles withN-Fluorobenzenesulfonimide

Abstract

A highly efficient amidation reaction of heterocycles with N-fluorobenzenesulfonimide (NFSI) has been developed, presumably proceeding via C-H bond activation. Cuprous iodide was employed as the catalyst, and various α-amidated heterocycle derivatives have been generated in good to excellent yields. This chemistry endowed an economic method of synthesis of valuable amidated heterocycles through a direct C-N bond-coupling processes.

Recent Trends in Copper‐Catalyzed C−H Amination Routes to Biologically Important Nitrogen Scaffolds

“…The copper‐catalyzed α‐amidation of 5‐membered aromatic heterocycles with N ‐fluorobenzenesulfonimide 99 was reported by Pan and co‐workers recently (Scheme ) . Copper iodide promoted this efficient catalytic cascade C−H activation followed by C−N bond formation.…”

Iron‐catalyzed C(5)−H Imidation of Azole with N‐Fluorobenzenesulfonimide

“…After Zhang group disclosed a pioneering work on palladium‐catalyzed C−H imidation of anilides with commercially available N ‐fluorobenzenesulfonimide (NFSI) in 2011, Ritter group reported a breakthrough on Pd‐catalyzed C−H imidation with NFSI, which could occur on simple benzenes without any directing group, as well as on some heterarenes including thiophene, pyrrole and pyridine . Beside palladium, copper catalysts have been widely reported to realize this novel imidation by several groups, and the arene scope has been further expanded to furan, pyrimidine, purine, coumarin, flavone and quinoline, in addition to benzenes without directing group ,. In the presence or absence of external oxidant, this imidation with NFSI could alternatively be achieved without transition metal catalysis, but the arene scope was somehow limited to quinoline, indole and pyrrole (Scheme c)…”

Recent Advances in Copper-Catalyzed Radical C–H Bond Activation Using N–F Reagents

“…Among them, the interest in the use of N-F reagents for the direct amination of C aryl -H bonds has increased in recent years. 10,40 In 2014, Pan and co-workers 41 described the efficient amidation of heterocycles with copper(I) iodide as the catalyst and NFSI as the N-F reagent (Scheme 26). A mechanism was postulated that involved the formation of Cu(I), Cu(II), and Cu(III) complexes.…”