N-Heterocyclic Carbene-Palladium Complexes [(NHC)Pd(acac)Cl]: Improved Synthesis and Catalytic Activity in Large-Scale Cross-Coupling Reactions

• Published in: Advanced synthesis & catalysis Vol. 349; no. 14-15; pp. 2380 - 2384
• Main Authors: Marion, Nicolas, de Frémont, Pierre, Puijk, Iris M., Ecarnot, Elise C., Amoroso, Dino, Bell, Andrew, Nolan, Steven P.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 08.10.2007; WILEY‐VCH Verlag; Wiley
• Subjects: Chemistry; Chemistry, Applied; Chemistry, Organic; cross-coupling; large-scale; N-aryl amination; N-heterocyclic carbene; palladium; Physical Sciences; Science & Technology; α-ketone arylation; KETONE; ALPHA-ARYLATION; n-aryl amination; N-heterocyclic; carbene; SUZUKI-MIYAURA; LIGANDS; BUCHWALD-HARTWIG; (NHC)PD(ALLYL)CL NHC; cross-coupling; CHEMISTRY; palladium; large-scale; a-ketone arylation
• ISSN: 1615-4150; 1615-4169
• DOI: 10.1002/adsc.200700195

From two commercially available starting materials, improved one‐step, multigram‐scale syntheses of [(IPr)Pd(acac)Cl] [IPr=N,N′‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene; acac=acetylacetonate] and [(IMes)Pd(acac)Cl] [IMes=N,N′‐bis(2,4,6‐trimethylphenyl)imidazol‐2‐ylidene] are described. The catalytic activity of both complexes in cross‐coupling reactions has been examined. The most active pre‐catalyst, [(IPr)Pd(acac)Cl], has allowed for efficient large‐scale (10 mmol) Buchwald–Hartwig and α‐ketone arylation reactions to be carried out.