Copper‐ or Iron‐Catalyzed Arylation of Phenols from respectively Aryl Chlorides and Aryl Iodides

Abstract

The first general entry into copper‐catalyzed arylation of phenols from aryl chlorides is the principal outcome of the study presented in this article. The use of the 2,2,6,6‐tetramethyl‐3,5‐heptanedione (1) as ligand is the key to the success of this reaction. An additional finding of this study, touched upon only briefly here, is the 1/Fe‐catalyzed arylation of phenols from aryl iodides (R=a donating or an electron‐withdrawing group).

Copper(I) Phenoxide Complexes in the Etherification of Aryl Halides

“…All these complexes appear to exist in an ionic form in the solid state and in the polar solvents that are often used for copper-catalyzed coupling of phenoxides. [24][25][26][27][28][29][30] This ionic form contains two Cu I sites, one bound by two chelating, dative ligands, and one by two phenoxides. In contrast to prior proposals of the reaction of anionic phenoxide complexes of copper, the isolated anion containing an ammonium counter-ion did not react with iodoarenes in high yields.…”

CuBr/N,N‐Dimethylglycine‐Catalyzed Coupling Reaction of 2‐Chlorotrifluoroacetanilides with Phenols at Mild Conditions

“…Generally, both electron-rich and electron-deficient phenols were compatible with these reaction conditions, delivering the corresponding diaryl ethers with good to excellent yields (Entries [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Noteworthy is that some sterically hindered phenols, such as 2-substituted phenols and 2,4,6-trimethylphenol, also worked well to provide 3k-3n in about 70% yield (Entries 10-13).…”

“…[2][3][4] However, for less expensive aryl chlorides, ligand-effect has been found less effective and therefore their coupling reactions with nucleophiles still required higher temperatures to complete. [5][6][7] For examples, copper-catalyzed coupling of aryl chlorides and phenols only took place at 120-135 ℃ by using TMHD 5 or (2-pyridyl)acetone 6 as the ligand.…”

Copper‐Catalyzed Ligand Promoted Ullmann‐Type Coupling Reactions

“…Recently, L18 was shown to be able to make inactive aryl chlorides work for the arylation of phenols (entry 6) [54] , and β -keto ester ( L19 ) [27] was revealed as an excellent promoter for diaryl ether formation (entry 7). Room temperature diaryl ether formation for some special substrates has been observed by Ma and coworkers (Scheme 9.5 ).…”