Cross-dehydrogenative coupling reactions between arenes (C–H) and carboxylic acids (O–H): a straightforward and environmentally benign access to O-aryl esters

Abstract

Transition-metal catalyzed cross-dehydrogenative-coupling encompass atom economical methods for the construction of various carbon–carbon and carbon–heteroatom bonds by combining two C(X)–H (X = heteroatom) bonds.

Functionalization of graphene oxide with a hybrid P, N ligand for immobilizing and stabilizing economical and non-toxic nanosized CuO: an efficient, robust and reusable catalyst for the C–O coupling reaction inO-arylation of phenol

“…The O -arylation reaction of phenol is a valuable process in synthetic organic chemistry and also in the preparation of many industrially important products. 57–59 The GO–PN–CuO nanocatalyst offers a wide substrate scope in the C–O coupling of phenol or its derivative with various substituted aryl chlorides and bromides at a very low Cu loading of 2.25 mol%, determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Preliminary experiments were carried out using 4-bromobenzaldehyde and phenol for optimizing the reaction conditions (Table 1) including solvents, bases, time and catalysts.…”

“…Diaryl ethers and their derivatives are very important structural motifs as they have widespread applications in pharmaceuticals, polymer industries, biologically active natural products and materials science. 57,58 Generally, diaryl ethers are prepared using copper-mediated Ullmann coupling which is a nucleophilic substitution reaction of phenol molecules with aryl halides. This method requires harsh reaction conditions such as a high temperature (>200 °C), excessive use of phenol, a long reaction time and use of a stoichiometric amount of copper.…”

Metal-metalloid bond containing complexes of the bulky organotellurium ligand: applications in catalysis of C–O coupling and aldehyde to amide transformation reactions

“…12,13,[38][39][40] This reaction is an efficacious method to synthesize O-arylated products which finds usefulness in biological, pharmaceutical, synthetic, material science, agrochemical and polymer applications. 41,42 The diaryl ethers that are obtained as products act as building blocks for a wide variety of natural and synthetic organic compounds. Because of their strong hydrophobic nature, adequate molecular flexibility, good lipid solubility, cell membrane penetration, and metabolic stability, they are commonly used in chemicals of medicinal, agrochemical or technological interest.…”

C(sp3)–H oxygenation via alkoxypalladium(ii) species: an update for the mechanism

“…The development of approaches for direct C–O formation of unactivated C(sp 3 )–H remains a fundamental challenge in synthetic chemistry owing to the high bond dissociation energy of the aliphatic C–H bonds; solving this problem is highly desirable considering the great manipulation potential of organic compounds. 1 In the past decade, Pd-catalyzed C(sp 3 )–H oxygenation has been proven to be a promising way to tackle this challenge through a combination of various oxidants such as PhI(OAc) 2 , 2 K 2 S 2 O 8 , 3 and N -fluoropyridinium 4 ( Scheme 1a ). In 2004, Canty's group reported the generation of the 1 H NMR-detectable alkylpalladium( iv ) intermediate (Pd IV (O 2 CPh) 2 Me 2 (L 2 )) from Pd II Me 2 (L 2 ) using (PhCO) 2 O 2 as an oxidant.…”