Palladium complexes catalyst, Grignard reagent alkylation

Similar to nickel catalysts, palladium complexes that have a chiral phosphine ligand enable asymmetric-coupling reactions of secondary-alkyl Grignard reagents and organic halides [246,256,257]. A study giving excellent e.e.s was selected [Eq. (173) 408] from relevant works [359,363,369]. 

Since the reaction can proceed at ambient temperature, some electrophilic functional groups can be present in the alkyl electrophiles, as exempUfied by products 1-3. Further optimizations studies on this catalyst led to the development of N-heterocychc carbene (NHC)-derived palladium catalysts for arylations of alkyl chlorides. In this system, it is assumed that the initial reaction of a precatalyst [Pd(IMes)(NQ)]2 4 and an aryl Grignard reagent should generate a coordinatively unsaturated palladium-carbene complex, which is the actual palladium-catalysis complex with high catalytic activity [9]. 

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