Ni-Catalyzed Remote Radical/Cross-Electrophile Coupling Cascade for Selective C(sp³)–H Arylation

Abstract

An innovative 1,5-HAT cascade strategy has been advanced for the nickel-catalyzed distal arylation via cross-electrophile coupling. Through specific migration, the remote C­(sp3)–H bond is regioselectively activated, and Ar–I as the available electrophile is used for the construction of the C­(sp3)–C­(sp2) bond. This method also has broad applicability for benzylic and aliphatic N-fluorocarboxamides with yields up to 80%. Furthermore, a series of control experiments demonstrated that this reaction is probably initiated by a radical process.

Amidyl Radical Directed γ‐C(sp3)−H Functionalization with Silyl Enol Ethers via Photoredox Catalysis

“…Introduction of these N-functionalized amide substrates has led to a greater expansion of the application of nitrogen radicals. Zhu, [7] Alexanian, [8] Li [9] and other groups [10] employed the cleavage of N-haloamines (F, Cl) bonds for amidyl radical formation and subsequent 1,5-hydrogen atom transfer (1,5-HAT) reaction (Figure 1a, Eq 2). But the instability of the N-haloamines has nevertheless limited to some extent their synthetic applications.…”

Copper-catalyzed intramolecular iminolactonization cyclization reactions of remote C(sp3)–H bonds in carboxamides

“…10 a Then, Ye and co-workers reported a cobalt catalyzed intramolecular C–H amination of N -fluorosulfonamides. 10 b Apart from cyclization, the transition-metal catalyzed site-selective intermolecular C(sp 3 )–H functionalization of N -fluoroamides with a wide range of nucleophiles has also been developed, such as (hetero)arylation, 11 alkynation, 12 alkylation, 7,13 amination, 13 b ,14 cyanation 15 and other transformations. 16 Inspired by these elegant precedents, we herein present an intramolecular iminolactonization cyclization reaction of δ C(sp 3 )–H bonds under copper catalysis via radical-involved 1,5-HAT cascades (Scheme 1d).…”

Redox Neutral Radical-Relay Nickel-Catalyzed Remote Carbonylation

“…For example, Zhu’s group published a copper-catalyzed arylation of distant C­(sp 3 )–H bonds via 1,5-HAT routes . Recently, our research group used N–F substrates as the N-radical precursors to deliver the C-centered radicals, which are immediately coupled with the alkene to construct specific chemical structures . Despite the tremendous progress in this area, the site-selective multicomponent carbonylation of remote C­(sp 3 )–H bonds still warrants extensive exploration.…”