Metal-free amidation of ether sp³ C–H bonds with sulfonamides using PhI(OAc)₂

Abstract

Ether C–H bonds can be selectively amidated using simple sulfonamides and iodine oxidants in the absence of a metal catalyst.

Direct Synthesis of Hemiaminal Ethers via a Three‐Component Reaction of Aldehydes, Amines and Alcohols

“…Hemiaminals are molecules of high relevance due to their intermediacy in synthetic protocols involving coupling10 and cyclization11 reactions or enzymatic processes,12 for instance. Their preparation has been described by α‐CH amidation reactions of ethers via insertion with metal‐based8 or metal‐free protocols,13 involving hypervalent iodine oxidants or additives, and affording undesired by‐products. At variance with that, the simple method described herein provides an excellent atomic economy, given that only a molecule of H 2 O is eliminated from the reactants.…”

Recent Progress in the Construction of C−N Bonds via Metal‐Free Radical C(sp3)−H Functionalization

“…The amidation of ethers under transition metal‐free conditions has been described by the Crabtree/Gunnoe group in 2014 (Scheme ) . This work was free of precious metal catalysts and proceeded to completion in a short time (2–10 h).…”

Recent Functionalizations of Primary Sulfonamides

“…The sulfonamide moiety is a common building block in organic synthesis [1][2][3][4][5][6][7][8][9][10][11][12][13][14] and an essential functional group in drug design. [15][16][17][18][19] Sulfonamides have a wide range of medical applications due to their anti-inflammatory, [15][16][17] antibacterial, [18][19][20][21] antimicrobial, [22][23][24] anticancer, [25][26][27][28][29][30][31] antimalarial, 32 and antipsychotic activities.…”

“…Taking the data together along with literature reports, the authors illustrated two possible pathways for the formation of the key species 63.1, namely a single-electron-transfer (SET) approach or a hydrogen-atom-transfer (HAT) approach (Scheme 63). 4…”