SCS-pincer palladium-catalyzed auto-tandem catalysis using dendritic catalysts in semi-permeable compartments

Novel monometallic and dendritic SCS-pincer palladium complexes 2, 3 and 4 have been synthesized in good yields (60-89%) and high purity (palladium loading >97%). These complexes were successfully used as catalysts in the stannylation of cinnamyl chloride with hexamethylditin and in the catalytic auto-tandem reaction consisting of this stannylation followed by an electrophilic addition with 4-nitrobenzaldehyde, showing similar reaction rates and selectivities for all complexes. Dendritic complex 4 has furthermore been used in the compartmentalized catalysis of single and auto-tandem reactions, allowing catalyst reuse for four consecutive runs.