The Ullmann Ether Condensation

Moroz, A. A.; Shvartsberg, M. S.

doi:10.1070/rc1974v043n08abeh001845

Cited by 102 publications

(48 citation statements)

References 144 publications

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“…The benzophenone derivatives are commonly accessible through condensation by Friedel-Crafts acylation a) [27] of an appropriate substituted benzoyl chloride with a phenolic derivative [28] and is followed by the cyclization step b) that involves a nucleophilic substitution [8,28] or a nucleophilic addition-elimination [29] of 2,2'-dioxygenated benzophenones, or an oxidative process (X=H) [30]. The diaryl ether synthesis (Ullmann condensation) c) [31] uses the reaction of sodium phenolates with benzoic acids bearing halogen in the ortho position, and the ring formation is accomplished by electrophilic cycloacylation of the 2-aryloxybenzoic acids d) [32]. Because intermolecular acylation reactions give generally higher yields than Ullmann ether syntheses, the most prevalent strategy for xanthone synthesis is acylation, followed by cyclization to form the heterocyclic ring [for a practical comparative example see 33].…”

Section: Classical Methodsmentioning

confidence: 99%

Synthesis of Xanthones: An Overview

Sousa¹,

Pinto

2005

CMC

125

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Among the known synthetic routes to obtain xanthones, the Grover, Shah, and Shah reaction, the cyclodehydration of 2, 2'-dihydroxybenzophenones and electrophilic cycloacylation of 2-aryloxybenzoic acids are the most popular methods. Due to important biological applications of xanthones, some synthetic strategies leading to more complex derivatives have been widely explored in the past years. Thus, the purpose of this review is to report some recent improvements of the classical synthetic methods as well as of some non-classical methods to obtain simple oxygenated xanthones. The strategies for introduction of substituents into the xanthonic nucleus are also summarized. Furthermore, different approaches used to synthesize complex structures, with an emphasis on the total synthesis of bioactive natural products, accomplished in the last twenty years, are also discussed. Besides the synthesis of xanthones, the reactivity of the xanthonic nucleus and its role as a key intermediate for the synthesis of other important classes of compounds are also highlighted.

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Section: Classical Methodsmentioning

confidence: 99%

Synthesis of Xanthones: An Overview

Sousa¹,

Pinto

2005

CMC

125

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“…Various synthetic approaches have been demonstrated for the synthesis of PAEs since early days [35][36][37][38][39][40]. PAEs were synthesized by Ullmann condensation between bisphenols and aryl bis-halide monomers using Cu(I) salt/pyridine as catalyst [36].…”

Section: Synthesis Characterization and Properties Of The Polymersmentioning

confidence: 99%

Fluorinated Poly(Arylene Ether)s

Ghosh

Mukherjee

Ghosh

et al. 2015

Handbook of Specialty Fluorinated Polymers

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“…26 Also, many diaryl ethers are important structural motifs found in a variety of naturally occurring medicinally active compounds including riccardin B, 27 tetramethylmagnolamine, 28 K-13, 29 piperazinomycin 30 and perrottetine. [32][33][34] On the other hand, many of palladium-reactions described the use of organic bromides, iodides and triates for the preparation of diaryl ethers. In the recent years, several improved protocols for O-arylation of phenols have been reported using palladium or copper as the catalyst.…”

Section: Introductionmentioning

confidence: 99%

Palladium nanoparticles supported on natural nanozeolite clinoptilolite as a catalyst for ligand and copper-free C–C and C–O cross coupling reactions in aqueous medium

et al. 2014

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In this article, Pd 0 -nanoparticles supported on natural nanozeolite clinoptilolite (CP) were successfully synthesized, and the catalytic activity of the nanocatalyst was investigated in C-C and C-O coupling reactions, namely the Sonogashira and Ullmann condensation reactions in an aqueous medium. The nanocatalyst was characterized by various techniques such as powder-XRD, BET, SEM, TEM, HRTEM, TEM-EDS, ICP-OES and XPS. From an electron microscopy (SEM) study it can be inferred that the particles are mostly spherical or of ellipsoidal shape and have diameters ranging from 25 to 80 nm. A HRTEM study reveals that Pd 0 -nanoparticles supported on nanozeolite CP have an average diameter of $10 nm. The supported palladium nanoparticles showed excellent catalytic activity in the synthesis of aryl alkynes and diaryl ethers in high yields. In addition, the nanocatalyst could be recycled and reused several times without significant loss of catalytic activity.

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The Ullmann Ether Condensation

Cited by 102 publications

References 144 publications

Synthesis of Xanthones: An Overview

Synthesis of Xanthones: An Overview

Fluorinated Poly(Arylene Ether)s

Palladium nanoparticles supported on natural nanozeolite clinoptilolite as a catalyst for ligand and copper-free C–C and C–O cross coupling reactions in aqueous medium

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