Synthesis of diaryl ethers from tyrosine derivatives

Metal‐Free Arylation of Oxygen Nucleophiles with Diaryliodonium Salts

“…[37] The reaction required prolonged reaction times and high temperatures in protic solvents, which are detrimental to racemization-prone substrates, such as a-amino acid substituted phenols, common in natural products. [38] We envisioned that a mild and general arylation protocol could be developed with aprotic solvents and diaryliodoni-um triflates or tetrafluoroborates because salts with these anions are soluble in less-polar solvents. [39] This was indeed the case and our preliminary results on the arylation of phenols under mild and racemization-free conditions were recently reported.…”

Diaryl Ether Formation in the Synthesis of Natural Products

“…[118] It should be noted that, although the outcome is formally an S N Ar addition, the detailed reaction mechanism is more complicated. [118] It should be noted that, although the outcome is formally an S N Ar addition, the detailed reaction mechanism is more complicated.…”

“…[119] The conditions required for the preparation of the aryl iodonium salts limit their substitution patterns. [118,138] Nonetheless, the method is ideally suited for the construction of multiply halogenated, sterically congested diaryl ethers and has allowed a general and versatile synthesis of several bastadin members with all possible halogenation patterns (32)(33)(34) and without the limitations encountered in approaches based on oxidative phenol coupling (vide infra). Finally, the requirement for basic conditions, polar solvents (water, DMF), and elevated temperatures do not bode well for the application of this method to epimerization-prone substrates.…”

“…Treatment of diaryl iodonium salts with phenoxides to yield diaryl ethers has been known since the 1960s and was among the methods employed in glycopeptide-related synthetic studies (Scheme 2, X = I + Ar). [118] It should be noted that, although the outcome is formally an S N Ar addition, the detailed reaction mechanism is more complicated. [119] The conditions required for the preparation of the aryl iodonium salts limit their substitution patterns.…”

Die Synthese von Diarylethern: ein lange bestehendes Problem wurde gelöst

“…[14] Höhere Temperaturen erfordern dagegen die Bildung der Diarylether aus Aryliodoniumsalzen und Phenolaten (DMF, 90 8C) [15] und die Kupplung von Brombenzochinonen mit Phenolaten (DMF, 100 ± 110 8C), der sich eine Dithionitreduktion anschlieût. [16] Mann und Hartwig [17] beschrieben eine Palladium-katalysierte Verknüpfung von Natriumphenolaten und Elektronenmangel-Arylbromiden.…”