Biphenyl-2-ols undergo regioselectivemono- and diarylation upon a treatment with aryl iodides in the presence of a palladium catalyst in DMF using Cs2CO3 as a base to produce 1,1′ : 2′,1″-terphenyl-2-ol and 2′,6′-diphenylbiphenyl-2-ol and their derivatives. The reaction of 1-naphthol selectively occurs at its 8-position to give 8-aryl-1-naphthols. In the reaction of 2-naphthol with aryl bromides, diarylated
Metal Free, Direct and Selective Deoxygenation of α-Hydroxy Carbonyl Compounds: Access to α,α-Diaryl Carbonyl Compounds
作者:Sandeep、Paloth Venugopalan、Anil Kumar
DOI:10.1002/ejoc.202000142
日期:2020.5.10
A variety of α‐hydroxy‐α,α‐diaryl carbonylcompounds are selectively deoxygenated to give an important class of α,α‐diaryl carbonylcompounds using catalytic amount of aqueous HClO4 (70 %) and triethylsilane as hydride source.
Acetophenone and deoxybenzoin derivatives are selectively α‐arylated using a combination of very small amounts of palladium acetate and diphenylphosphine oxide as catalyst system and water as the only solvent. Target di‐ and triarylethanones are isolated virtually free of metal residues, and the reaction is amenable to gram‐scale. A mechanistic proposal based on TEM images, poisoning experiments, kinetic