- [Pd(Cl)2(P(NC5H10)(C6H 11)2)2] - A highly effective and extremely versatile palladium-based negishi catalyst that efficiently and reliably operates at low catalyst loadings
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[Pd(Cl)2(P(NC5H10)-(C6H 11)2]2] (1) has been prepared in quantitative yield by reacting commercially available [Pd(cod)(Cl)2] (cod = cyclooctadiene) with readily prepared 1-(dicyclohexylphosphanyl)piperidine in toluene under N2 within a few minutes at room temperature. Complex 1 has proved to be an excellent Negishi catalyst, capable of quantitatively coupling a wide variety of electronically activated, non-activated, deactivated, sterically hindered, heterocyclic, and functionalized aryl bromides with various (also heterocyclic) arylzinc reagents, typically within a few minutes at 100°C in the presence of just 0.01 mol% of catalyst. Aryl bromides containing nitro, nitrile, ether, ester, hydroxy, carbonyl, and carboxyl groups, as well as acetais, lactones, amides, anilines, alkenes, carboxylic acids, acetic acids, and pyridines and pyrimidines, have been successfully used as coupling partners. Furthermore, electronic and steric variations are tolerated in both reaction partners. Experimental observations strongly indicate that a molecular mechanism is operative.
- Bolliger, Jeanne L.,Frech, Christian M.
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experimental part
p. 11072 - 11081
(2010/11/16)
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- Arylzinc species by microwave assisted Grignard formation-transmetallation sequence: Application in the Negishi coupling
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Arylmagnesium species can be efficiently generated from magnesium turnings and aryl chlorides or aryl bromides under dielectric heating conditions. Subsequent microwave assisted transmetallation using ZnCl2-TMEDA afforded the corresponding arylzinc reagents. A sequential microwave assisted arylmagnesium formation-transmetallation-Negishi coupling protocol suitable for automated multiple parallel synthesis has been developed.
- Mutule, Ilga,Suna, Edgars
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p. 11168 - 11176
(2007/10/03)
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- Palladium-catalyzed borylation of phenyl bromides and application in one-pot Suzuki-Miyaura biphenyl synthesis
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(Chemical equation presented) The coupling reaction of pinacolborane with various aryl bromides in the presence of a catalytic amount of Pd(OAc) 2 together with DPEphos as ligand and Et3N as base provided arylboronates. High yields were obtained in the case of electron-donor substituted aryl bromides. The direct preparation of arylboronates allowed the one-pot, two-step synthesis of unsymmetrical biaryls in high yields.
- Broutin, Pierre-Emmanuel,Cerna, Igor,Campaniello, Maria,Leroux, Frederic,Colobert, Francoise
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p. 4419 - 4422
(2007/10/03)
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