Diaryl ethers synthesis: nano-catalysts in carbon-oxygen cross-coupling reactions

Abstract

The diaryl ether moiety is not only prevalent in a significant number of natural products and synthetic pharmaceuticals but also widely found in many pesticides, polymers, and ligands. Ullmann-type crosscoupling reactions between phenols and aryl halides are regarded as one of the most important methods for the synthesis of this important and versatile structural motif. In recent years, the use of nano-sized metal catalysts in this coupling reaction has attracted a lot of attention because of these catalysts with their high surface-to-volume ratio, high surface energy, and reactive morphology allows for rapid C-O bond formation under mild and ligand-free conditions. In this review we will highlight the power of these catalysts in Ullmann-type C-O cross-coupling reactions.

Organoselenium ligands for heterogeneous and nanocatalytic systems: development and applications

“…O-Arylation of phenol is an example of C-O coupling in which phenol couples with aryl halides to give diaryl ethers as the product and has various applications in pharmaceuticals, polymers 127 and agrochemicals. 127 For this reaction, a variety of copper based nanocatalytic 128 and heterogeneous catalytic systems are reported.…”

“…O-Arylation of phenol is an example of C-O coupling in which phenol couples with aryl halides to give diaryl ethers as the product and has various applications in pharmaceuticals, polymers 127 and agrochemicals. 127 For this reaction, a variety of copper based nanocatalytic 128 and heterogeneous catalytic systems are reported. 20,23 In order to avoid the harsh reaction conditions required during catalysis by Cu based systems, the researchers have focused on alternative metals (including palladium) too.…”

Cellulose nanocrystals-Palladium, a novel recyclable catalyst for coupling reaction

“…As such, Ullmann coupling reaction was introduced in 1901 for the synthesis of symmetrical biaryls using aryl iodides and copper as catalyst at high temperatures [4,5]. New Ullmann coupling reaction using aryl bromides/chlorides as reactants in presence of Zn powder and Pd as catalysts was developed later [6]. Ullmann reaction using Pd as catalyst indicated good performance for the synthesis of complicated organic molecules such as pharmaceuticals [7], medicine [8], polymers [9], alkaloids [10], and other advanced materials [11].…”

Methods for the direct synthesis of thioesters from aldehydes: a focus review

“…Since a number of advances and developments in the direct thioesterification of aldehydes have occurred from 1976 to present, a comprehensive review on this interesting research topic seems to be timely. In connection with our review articles on the formation of C-S bonds [11][12][13][14][15][16][17][18][19][20][21][22] and new methodologies in organic synthesis [23][24][25][26][27][28][29][30][31][32][33][34][35], in this Focus-Review, we will highlight recent progress on direct thioesterification of aldehydes with various thiol sources ( Figure 1), with special attention on the mechanistic aspects of the reactions. The cross-dehydrogenative coupling reactions of aldehydes with thiols are discussed first.…”