Goldberg aryl amidation

Turner and Poondra have described an efficient intramolecular one-pot and two-step Goldberg aryl amidation that gives access to useful AT-substituted oxindoles (Scheme 29) [96]. 

An efficient intramolecular, one-pot, two-step, Goldberg aryl amidation producing useful N-substituted oxindoles was recently described by Turner and Poondra (Scheme 15.61) [126]. 

A. Ullmann and Goldberg Reactions Copper-mediated Amination and Amidation of Aryl Halides... 

Some improvements in the traditional Goldberg reaction have been reported with microwave heating. For example, Lange and coworkers384 synthesized V-arylpiperazin-ones, piperazinediones and 3,4-dihydroquinolinones via amidation of aryl bromides. The... 

The copper-promoted arylation of amides is known as the Goldberg reaction. Similar to the traditional Ullmann reaction, this transformation suffered from high reaction temperatures and strictly Umited substrates. The introduction of suitable Ugands has changed this situation. 

Scheme 1.7 Copper-catalyzed arylation of amide 21 (Goldberg, 1906).

The use of ligated copper catalysts has dramatically improved the coupling of aryl halides with amides—the Goldberg reaction. . This reaction has been studied intensively because of the utility of the products and the limitations in scope and efficiency of the palladium-catalyzed coupling of aryl halides with amides. Moreover, it is the process that occurs with the broadest scope when conducted with certain ancillary ligands. 

The Goldberg catalysed Y-arylation of amides gives low yields and requires drastic reaction conditions, but the use of silica-supported copper improves reaction yields. The pyrazolodiazepin system has been A -hetero-arylated in this way using potassium acetate as a base (e.g. equation 4.8) [52]. 

Amides may be converted to iV-alkyl and iV-acyl derivatives by appropriate condensation reagents. C-Alkylations of amides can also be carried out to modify the carbon skeleton of a compound. N-arylamides may be prepared by the Goldberg reaction of an amide with an aryl halide in the presence of potassium carbonate and cuprous iodide. 

Abstract Although requiring the use of stoichiometric amounts of metal and harsh conditions, the copper-mediated coupling reactions of aryl halides with amines and phenols (Ullmann craidensatiOTis), amides and carbamates (Ullmann-Goldberg condensations), or activated methylene compounds (Ullmann-Hurtley condensations) have been for a long time useful methods for the formation of C(aryl)-N, C(aryl)-0, and C(aryl)-C bonds. In 2001, a renaissance of the Ullmann reaction has been initiated with the discovery of versatile new copper catalytic systems for C-C, C-N, or C-O coupling under mild temperature ccmditions. 

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