Chemistry - A European Journal · 2006 · 822 citations · 49 references
Natural SciencesChemistryCatalysisGreen ChemistryOrganic ChemistryCarbene ComplexesCatalyst PreparationCatalyst SynthesisCross-coupling ReactionsHeterocyclic ChemistryHeterocyclic CompoundsCatalysis By Carbene ComplexesHeteroaromatic CompoundsMild Reaction ConditionsNegishi CouplingPalladium CatalystsPalladium-catalyzed Cross-couplingSuzuki - Miyaura CouplingTransition-metal-catalyzed Heterocycle Synthesis
The synthesis of NHC-PdCl(2)-3-chloropyridine (NHC=N-heterocyclic carbene) complexes from readily available starting materials in air is described. The 2,6-diisopropylphenyl derivative was found to be highly catalytically active in alkyl-alkyl Suzuki and Negishi cross-coupling reactions. The synthesis, ease-of-use, and activity of this complex are substantial improvements over in situ catalyst generation and all current Pd-NHC complexes. The utilization of complex 4 led to the development of a reliable, easily employed Suzuki-Miyama protocol. Employing various reaction conditions allowed a large array of hindered biaryl and drug-like heteroaromatic compounds to be synthesized without difficulty.
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