Copper-Catalyzed Etherification of Arene C–H Bonds

Abstract

A method for direct, auxiliary-assisted alkoxylation and phenoxylation of β-sp2 C−H bonds of benzoic acid derivatives and γ-sp2 C−H bonds of amine derivatives is reported. The reaction employs (CuOH)2CO3 catalyst, air as an oxidant, phenol or alcohol coupling partner, DMF, pyridine, or DMPU solvent, and K2CO3, tetramethylguanidine, or K3PO4 base at 90–130 °C.

Copper‐Catalyzed Site‐Selective Intramolecular Amidation of Unactivated C(sp3)H Bonds

“…Furthermore, a secondary kinetic isotope effect was observed, thus suggesting that the sp 3 C À H bond cleavage of the amide 1 should not be the rate-limiting step in this catalytic process (Scheme 2 b). [12] On the basis of the above observation and the previous reports, [8,13] a plausible catalytic cycle of this transformation is proposed (Scheme 3). Coordination of 1 to a copper(II) species and subsequent ligand exchange in the presence of sodium benzoate generates the copper complex A, which forms the alkyl/Cu II species B by a cyclocupration process.…”

Copper-Mediated Intermolecular C–H/C–H and C–H/N–H Couplings via Aromatic C–H Cleavage

“…The use of the quinoline auxiliary overcomes this limitation, and phenol derivatives as well as easily-oxidizable allylic and benzylic alcohols can be employed (Eq. 39) [70]. Interestingly, with 3-aminophenol, the selective C-O formation over C-N formation is observed.…”

Copper‐Catalyzed or ‐Mediated CH Bond Functionalizations Assisted by Bidentate Directing Groups

“…[22] This reactione mploys (CuOH) 2 CO 3 as catalyst, air as an oxidant, phenolo ra lcohol as coupling partner, DMF,p yridine,o rD MPU as solvent, and K 2 CO 3 ,t etramethylguanidine,o rK 3 PO 4 as base at 70-130 8 8C. Ar ange of common functional groups on the arenes such as ester, amine,n itro,n itrile,a nd halogen groups were tolerated in this transformation.…”