38695-10-2

Upstream product

• 371-41-5 4-Fluorophenol 
• 121-69-7 N,N-dimethyl-aniline 
• 2561-25-3 4-(4-fluorophenoxy)-1-nitrobenzene 
• 586-77-6 4-bromo-N,N-dimethylaniline 
• 36160-82-4 4-(4-fluorophenoxy)aniline 
• 77-78-1 dimethyl sulfate 
• 67-56-1 methanol 

Relevant academic research and scientific papers

Electro-oxidative C(sp2)-H/O-H cross-dehydrogenative coupling of phenols and tertiary anilines for diaryl ether formation

The formation of diaryl ethers is generally achievedviatransition metal catalyzed etherification reactions (Ullmann, Chan-Lam, Buchwald-Hartwig) with prefunctionalized aryl halide substrates at elevated temperatures. Herein, we report a protocol for electrochemical C(sp2)-H/O-H cross-dehydrogenative coupling of phenols and tertiary anilines to synthesize diaryl ethers. The C(sp2) H/O-H coupling product can be obtained under metal- and oxidant-free conditions at room temperature in moderate to excellent yield (up to 83% yield) with high regioselectivity (>99% forpara-substitution) and with a broad substrate scope (22 examples).

Ullmann diaryl ether synthesis: rate acceleration by 2,2,6,6-tetramethylheptane-3,5-dione.

[reaction: see text]. In the copper salt catalyzed ether formation from aryl bromides or iodides and phenols, 2,2,6,6-tetramethylheptane-3,5-dione (TMHD) was found to greatly accelerate the ordinarily difficult reaction, making it occur under more moderate temperatures and reaction times. A series of aryl halides and phenols were shown to form ethers in NMP as the solvent, cesium carbonate as the base, and CuCl and TMHD as the catalysts. The reaction was shown to tolerate electron-rich aryl bromides and electron-neutral phenols.