Ullman ether synthesis

Pentafluorophenylcopper is representative of a series of fluori-nated organocopper compounds that are highly soluble in organic solvents, more thermally stable than their hydrocarbon analogs, and useful as synthetic intermediates. " Pentafluorophenylcopper has been used to introduce the pentafluorophenyl groups and as a reagent for an improved Ullman diphenyl ether synthesis. It is... 

Ullman reaction. Synthesis of biaryls by copper-induced coupling of aryl halides. Similar coupling of aryl halides with aroxides yields diaryl ethers. (A modification of the Fittig synthesis in which copper powder is used instead of sodium.)... 

Copper mediated Ullman reaction, usually requires harsh conditions. Wipf and Lynch reported arelatively mild biaryl ether synthesis via an SnAt (nucleophUic aromatic substimtion)... 

This reaction is related to the Rosemound-von Braun Nitrile Synthesis, Ullman Diaryl Ether Synthesis, and Ullmann Acridine Synthesis. 

The prevalence of the aniline functional group in alkaloid natural products of medicinal interest has inspired a number of metal-catalyzed strategies for the preparation of substituted anilines. One classical method, a variation of the Ullman aryl ether synthesis, features copper catalysis. This method generally suffers from harsh reaction conditions and limited substrate scope. Nonetheless, the simplicity of the transformation and the inexpensiveness of copper catalysis has prompted additional development of this strategy. For instance, cyclohexylphenylamine is formed in excellent yield from the copper(I) iodide-catalyzed amination of iodobenzene. ... 

Ullman reaction The synthesis of diaryls by the condensation of aromatic halides with themselves or other aromatic halides, with the concomitant removal of halogens by a metal, e.g. copper powder thus bromobenzene gives diphenyl. The reaction may be extended to the preparation of diaryl ethers and diaryl thio-ethers by coupling a metal phenolate with an aryl halide. 

The Ullman reaction has long been known as a method for the synthesis of aromatic ethers by the reaction of a phenol with an aromatic halide in the presence of a copper compound as a catalyst. It is a variation on the nucleophilic substitution reaction since a phenolic salt reacts with the halide. Nonactivated aromatic halides can be used in the synthesis of poly(arylene edier)s, dius providing a way of obtaining structures not available by the conventional nucleophilic route. The ease of halogen displacement was found to be the reverse of that observed for activated nucleophilic substitution reaction, that is, I > Br > Cl F. The polymerizations are conducted in benzophenone with a cuprous chloride-pyridine complex as a catalyst. Bromine compounds are the favored reactants.53,124 127 Poly(arylene ether)s have been prepared by Ullman coupling of bisphenols and... 

The Ullman reaction, discovered in 1903,2 is the prototype cross-coupling method for the synthesis of aryl ether... 

The first total synthesis of a sterigmatocystin type structure was reported by Roberts151. The furobenzofuran section73 used in the constmction was the same piece previously encountered95,117,142 in the synthesis of aflatoxin B2 (5). Ullman type coupling152 (pyridine/cuprous chloride) with bromoester (117), and subsequent hydrolysis, gave the diphenyl ether (118). Intramolecular cyclization to form... 

Direct coupling of vinyl halides and phenols under Ullman-type reaction conditions can be useful for the preparation of aryl vinyl ethers, and intramolecular version of this process has been applied to the synthesis of spirocyclic oxindoles through a sequence of intramolecular Ullman coupling and Claisen rearrangement reactions (eq 58). ... 

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