Recent Progress in Diaryl Ether Synthesis

Abstract

Diaryl ethers form an important class of organic compounds, both in life sciences and in the polymer industry. In general, diaryl ethers can be synthesized by means of copper-catalyzed Ullmann diaryl ether coupling, palladium-catalysed BuchwaldHartwig reaction, nucleophilic aromatic substitution, arylboronic acid diaryl ether coupling, oxidative coupling, and nucleophilic aromatic addition to metal-arene complexes. This review covers the progress in diaryl ether synthesis since 1999, with literature coverage through September 2005. 9Su mmary

Total synthesis of ochnaflavone

“…The most logical approach to the synthesis of 1 would be to start with the preparation of a diaryl ether. This functionality is present in many important bioactive natural compounds [19] and it is not surprising that a great amount of effort has been focused on the development and improvement of the methods to form diaryl ethers [20–21]. The Ullman reaction is often used to prepare diaryl ethers, but this reaction has the disadvantages of high reaction temperatures and intolerance to a wide variety of functional groups, with the major weakness being the inconsistency in the products obtained by the use of different copper sources [22–24].…”

Ethers from esters; from exceptional transformation to synthetic method

“…32 Interestingly, we have successfully applied Pd-catalyzed O-alkylation of complex macrocyclic alcohols by allyl-tert-butylcarbonate. 33,34 Diaryl ethers, 9,35 aryl alkyl ethers 36 and enol ethers 37 can be synthesized by means of a palladium-catalyzed Buchwald-Hartwig reaction. Broad application of this metal-catalyzed coupling reaction has mainly been achieved by developing ever more effective ligands for the catalytic complexes, starting from dinitrogen ligands to mono-and bidentate phosphines, and -donor alkenes, dba (dibenzylideneacetone) in particular.…”

Synthesis and Structure of New Compounds NSAIDs-Like Using a Heterogeneous Recyclable Catalyst

“…There are several ways to synthesis of aryl ethers is typically achieved via a nucleophilic aromatic substitution (NAS) process or transition metal catalyzed Ullmann-type [5,6] and Hartwig [7,8] or Buchwald-type [9,10] O-arylation reactions. The NAS approach requires the use of phenoxide to displace aryl fluorides or chlorides that are activated by strong electron withdrawing groups (EWG) located in the ortho, para, or, in rare cases, meta positions.…”