Suzuki-Miyaura coupling with palladium carbenes

Initial research in this area focused on the use of zerovalent Pd2(dba)3 as the palladium source, the carbene IMes, and CS2CO3 as base [43]. This reagent combination afforded a 59% yield in the coupling of 4-chlorotoluene with phenylboronic acid. The catalytic protocol could be simplified by the use of air-stable IMes-HCl that is deprotonated in situ with CS2CO3 isolated yields for the Suzuki-Miyaura coupling then reached >95% (Scheme 8). Subsequently a further simplification of the catalytic system was achieved, by extension of the reaction to air-stable Pd(II) precursors [44]. 

On the nature of the active species in palladium catalyzed Mizoroki-Heck and Suzuki-Miyaura couplings (particularly, Pd complexes with imi-nopyridine and N-heterocyclic carbenes as ligands) 06ASC609. 

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