Reactions Goldberg

N-Arylpiperazin-2-ones, N-arylpiperazin-2,5-diones and N-aryl-3,4-dihydro-quinolin-2(lff)-ones have been synthesized via a microwave-enhanced Goldberg reaction [105]. N-arylation reactions with 4-benzylpiperazin-2-one and 4-benzylpiperazin-2,5-dione performed in the microwave (reflux conditions) were tremendously accelerated in comparison with the same transformations performed under classical heating at reflux (Schemes 103 and 104). The phenylation of 3,4-dihydroquinolin-2(lH)-one under microwave irradiation was also faster but less pronounced. 

With ammonia (refs. 14 - 25), alkyl (refs. 26 - 28) or arylamines (refs. 29 - 44) as well with amides (refs. 37,45-49) (the Goldberg reaction (ref. 50)) the reaction affords substituted anilines. 

It has also proved possible to close larger rings in this manner 8 and even 12-membered. Triarylamines have been prepared in a similar manner from Arl and Ar NLi, even with unactivated Arl. In the Goldberg reaction, an aryl bromide reacts with an acetanilide in the presence of K2CO3 and Cul to give an N-acetyl-diarylamine, which can be hydrolyzed to a diarylamine ArBr-I- Ar NHAc—> ArAr NAc. ... 

The copper-catalyzed addition of amines and amides Goldberg Reaction) are placed in this section ... 

K. Kunz, U. Scholz, D. Ganzer, Renaissance of Ullmann and Goldberg Reactions - Progress in Copper Catalyzed C-N-, C-O- and C-S-Coupling, Synlett 2003, 2428-2439. 

A. Ullmann and Goldberg Reactions Copper-mediated Amination and... 

I. Copper-catalyzed Reaction of Amides (Goldberg Reaction). 519... 

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... 

One other example of alkane oxidative addition to a higher oxidation state late transition metal has been reported by Goldberg. Reaction of the trispyra-zolylborate complex K[r 2-Tp PtMe2] with B(C6F5)3 leads to the abstraction of a methyl anion and the formation of a transient species that adds to the C-H bonds of benzene, pentane, or cyclohexane (Eq. 15). This result provides the first example of the intermolecular addition of a C-H bond to a Ptn species to give a stable PtIV product [71]. Earlier work by Templeton had demonstrated that the trispyrazolylborateplatinumdialkylhydride product would be stable [72]. 

Renaissance of Ullmann and Goldberg reactions — progress in copper catalyzed C—N-, C-O- and C—S-coupling , Kunz, K., Scholz, U. and Ganzer,... 

N-aryl-2-piperazmones are of great interest as famesyl-transferase inhibitors, and both N-aryl-2-piperazinones and N-aryl-2,5-piperazinediones are synthetic precursors of N-arylpiperazines which are key elements in monoamine receptor-active drugs. Lange et al. enhanced the Goldberg reaction with microwaves for synthesis of N-arylpiperazinones, N-arylpiperazinediones, and N-aryl-3,4-dihydroquinolines [88]. Microwave irradiation greatly accelerates the reaction when NMP is used as solvent. 

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. 

The MW-enhanced Goldberg reaction of 3,4-dihydro-l//-quinolin-2-one (340) with bromobenzene produced l-phenyl-3,4-dihydro-lFf-quinolin-2-one 341 within 30min at 200°C, followed by Ih at 190°C (Scheme 69) (02TL1101) 4h were required under conventional heating. 

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