[Pd(NHC)(acac)Cl]: Well-Defined, Air-Stable, and Readily Available Precatalysts for Suzuki and Buchwald–Hartwig Cross-coupling (Transamidation) of Amides and Esters by N–C/O–C Activation

A general class of well-defined, air-stable, and readily available Pd­(II)-NHC precatalysts (NHC = N-heterocyclic carbene) for Suzuki and Buchwald–Hartwig cross-coupling of amides (transamidation) and esters by selective N–C/O–C cleavage is reported. Since these precatalysts are highly active and the easiest to synthesize, the study clearly suggests that [Pd­(NHC)­(acac)­Cl] should be routinely included during the development of new cross-coupling methods. An assay for in situ screening of NHC salts in this cross-coupling manifold is presented