A highly effective hydroxylation reaction of arylhalides with water under synergistic organophotoredox and nickel catalysis is reported. The OH group of the resulting phenols originates from water, following deprotonation facilitated by an intramolecular base group on the ligand. Significantly, aryl bromides as well as less reactive aryl chlorides served as effective substrates to afford phenols with
A nickel‐catalyzedcross‐coupling between (hetero)arylborons and unactivated 1‐bromo‐1,1‐difluoroalkanes has been developed. The use of two ligands (a bidentate bipyridine‐based ligand, 4,4′‐ditBu‐bpy, and a monodentate pyridine‐based ligand, DMAP) offers a highly efficient nickel‐based catalytic system to prepare difluoroalkylated arenes which have important applications in medicinal chemistry.
Radical–anion coupling through reagent design: hydroxylation of aryl halides
作者:Andrew J. Greener、Patrycja Ubysz、Will Owens-Ward、George Smith、Ivan Ocaña、Adrian C. Whitwood、Victor Chechik、Michael J. James
DOI:10.1039/d1sc04748e
日期:——
The design and development of an oxime-based hydroxylation reagent, which can chemoselectively convert aryl halides (X = F, Cl, Br, I) into phenols under operationally simple, transition-metal-free conditions is described. Key to the success of this approach was the identification of a reducing oxime anion which can interact and couple with open-shell aryl radicals. Experimental and computational studies
Nickel‐Mediated Trifluoromethylation of Phenol Derivatives by Aryl C−O Bond Activation
作者:Wei‐Qiang Hu、Shen Pan、Xiu‐Hua Xu、David A. Vicic、Feng‐Ling Qing
DOI:10.1002/anie.202004116
日期:2020.9.7
trifluoromethylation reactions. Tremendous efforts have focused on copper‐ and palladium‐mediated/catalyzed trifluoromethylation of aryl halides. In contrast, no general method exists for the conversion of widely available inert electrophiles, such as phenol derivatives, into the corresponding trifluoromethylated arenes. Reported herein is a practical nickel‐mediated trifluoromethylation of phenol derivatives with readily
A highly efficient hydroxylation of (hetero)aryl halides using water as a hydroxyl source via Ni catalysis promoted by PhSiH3 under thermal catalysis is reported. This methodology provides a general procedure to obtain diverse multifunctional pharmaceutically phenols and polyphenols, some of which are proven challenging to be synthesized using literature methods. Mechanism studies demonstrated that