Cu-Catalyzed Arylation of Phenols: Synthesis of Sterically Hindered and Heteroaryl Diaryl Ethers

Abstract

Cu-catalyzed O-arylation of phenols with aryl iodides and bromides can be performed under mild condition in DMSO/K3PO4 using picolinic acid as the ligand for copper. This method tolerates a variety of functional groups and is effective in the synthesis of hindered diaryl ethers and heteroaryl ethers.

A Recyclable Cu-MOF-74 Catalyst for the Ligand-Free O-Arylation Reaction of 4-Nitrobenzaldehyde and Phenol

“…The traditional synthesis is based on the Ullmann cross-coupling reaction of phenols with aryl halides, catalyzed by copper salts [3]. However, homogeneous copper-mediated coupling reactions are limited by the large amount of catalyst needed and harsh reaction conditions [4,5,6,7].…”

Regioselective Multicomponent Synthesis of 2,4,6‐Trisubstituted Phenols from Fischer Alkynyl Carbene Complexes

“…[6] These compounds are important in the defense against predators and in other survival strategies; [7] they also have synthetic applications (mimetic studies of metalloenzymes and the construction of bulky protecting groups), [8,9] and applications as anticancer drugs, [10] antioxidants, [11] biopesticides, [12] tannins, [13] and as flavor enhancers for beverages. [14] These molecules are attractive not only for their potential pharmacological uses, [15] but also as they may be transformed into other interesting substrates, such as ortho [16] and para [17] quinones, aromatic ethers, [18] and ligands for metal centers. [19] Some of the more representative pathways for obtaining the phenol core are illustrated in Scheme 1.…”

Recent Synthetic Developments and Applications of the Ullmann Reaction. A Review

“…In 2010, Buchwald and Maiti 49 described a simple and effective protocol for the Ullmann coupling between sterically hindered phenols and aryl halides (X = I; Br). Inexpensive picolinic acid ( L25 ) was employed as the ligand in this method, which tolerated a variety of functional groups (Table 2, Entry 3).…”