Synthesis of biaryls via the Suzuki-Miyauracoupling (SMC) reaction using nitroarenes as an electrophilic coupling partners is described. Mechanistic studies have revealed that the catalytic cycle of this reaction is initiated by the cleavage of the aryl-nitro (Ar-NO2) bond by palladium, which represents an unprecedented elemental reaction.
Put a ring on it! The arylation of aliphatic alcohols and hydroxide with diaryliodoniumsalts, to give alkyl aryl ethers and diaryl ethers, has been studied using experimental techniques and DFT calculations. Aryne formation and alcohol oxidation pathways were observed in parallel to arylation, and additives to avoid by-product formation originating from arynes have been found. A novel, direct nucleophilic
A simple, metal- and ligand-free procedure for the Ullmann-type C–O coupling reactions has been achieved by allowing aryl bromides to react with a variety of phenols in the presence of t-BuOK. Moderate to excellent yields of O-arylation products are obtained under mild conditions in a short time. In addition, two examples of C–N coupling reactions are also reported. A benzyne mechanism is proposed
Diaryl Ether Formation Merging Photoredox and Nickel Catalysis
作者:Le Liu、Cristina Nevado
DOI:10.1021/acs.organomet.1c00018
日期:2021.7.26
Photoredox and Ni catalysis are combined to produce diaryl ethers under mild conditions. A broad range of aryl halides and phenol derivatives are cross-coupled in the presence of a readily available organic photocatalyst and NiBr2(dtbpy). Symmetrical diaryl ethers have also been directly obtained from aryl bromides in the presence of water. Mechanistic investigations support the involvement of Ni(0)
Reactions of Selenurane [10-Se-4 (C4)] with Alcohols, Thiols and Selenol. A Quest for Formation of a New a-Selenurane [10-Se-4 (C3O)], [10-Se-4 (C3S)] or [10-Se-4 (C3Se)]
作者:Soichi Sato、Naomichi Furukawa
DOI:10.1246/cl.1994.889
日期:1994.5
Bis(2,2′-biphenylylene)selenurane readily reacts with various alcohols, phenols, thiols and selenol to give ligand coupling or ipso-substitution products under mild conditions via a two-step mechanism involving a σ-selenurane [10-Se-4 (C3O)], [10-Se-4 (C3S)] and [10-Se-4 (C3Se)] or corresponding selenonium salts as intermediates.