Metal-free C–H Activation over Graphene Oxide toward Direct Syntheses of Structurally Different Amines and Amides in Water

Abstract

Unprecedented metal-free synthesis of a variety of amines and amides is reported via amination of C(sp 3 )−H and C(sp 2 )−H bonds. The strategy involves graphene-oxide/I 2 -catalyzed nitrene insertion using PhINTs as a nitrene (NT) source in water at room temperature. A wide range of structurally different substrates, viz., cyclohexane, cyclic ethers, arenes, alkyl aromatic systems, and aldehydes/ketones, having an α-phenyl ring have been employed successfully to afford the corresponding nitrene insertion product in good yield, albeit low in few cases. The envisaged method has superiority over others in terms of its operational simplicity, metal-free catalysis, use of water as a solvent, ambient reaction conditions, and reusability of the catalyst.

Reactivity of Hypervalent Iodine(III) Reagents Bearing Transferable N‐Based Groups

“…Recently, Rai and co-workers [53] reported the metal-free synthesis of amines and amides via amination of C(sp 3 )À H and C(sp 2 )À H bonds using PhI=NTs 7 a as a nitrene source (Scheme 14). The nitrene insertion was accomplished using PhI=NTs 7 a in combination with graphene oxide (GO) and molecular iodine, as catalytic cocktail for the CÀ N coupling/CÀ H activation.…”

Recent advances in metal directed C–H amidation/amination using sulfonyl azides and phosphoryl azides

“…This shift has also prompted a reevaluation of the traditional definition of “C–H activation” as it encompasses new mechanistic pathways and reactivity profiles. 49,50…”

“…This shift has also prompted a reevaluation of the traditional definition of "C-H activation" as it encompasses new mechanistic pathways and reactivity profiles. 49,50 2.1.3 Sigma and agnostic complexes. Sigma and agostic interactions play a crucial role as the initial step preceding C-H bond activation.…”

Imino-λ3-iodane-Triggered Oxidative Ring-Opening of 2H-Indazoles to ortho-N-Acylsulfonamidated Azobenzenes

“…Based on the above control experiments and previously reported literature, ,,, a tentative mechanistic proposal of this transformation is outlined in Scheme . Initially, an electrophilic addition of PhINTs to the electronic rich C-3 center of 2-(4-chlorophenyl)-2 H -indazole ( 1e ) occurs to form the intermediate A .…”