- Rapid room temperature Buchwald-Hartwig and Suzuki-Miyaura couplings of heteroaromatic compounds employing low catalyst loadings.
Rapid room temperature Buchwald-Hartwig and Suzuki-Miyaura couplings of heteroaromatic compounds employing low catalyst loadings.
Chemistry (Weinheim an der Bergstrasse, Germany) (2006-04-22)
Oscar Navarro, Nicolas Marion, Jianguo Mei, Steven P Nolan
PMID16628762
ABSTRACT
The use of second-generation [(NHC)Pd(R-allyl)Cl] complexes for Suzuki-Miyaura and Buchwald-Hartwig cross-coupling reactions involving heteroaromatic halides at room temperature is reported. The first examples of room temperature Suzuki-Miyaura cross-coupling of deactivated aryl chlorides with alkenyl boronic acids are also disclosed. Terminal substitution at the allyl moiety of the palladium complex facilitates its activation at room temperature leading to very active catalytic species enabling the present catalytic transformations to be performed rapidly using very mild reaction conditions. Catalyst loadings can be as low as 10 ppm for the Buchwald-Hartwig aryl amination and 50 ppm for the Suzuki-Miyaura reaction.