An efficient, selective and recoverable catalytic system for ligand-free aqueous Heck reactions using hydroxypropylated cyclodextrins (HPCDs) and palladium on calcium carbonate (Pd/CaCO 3 ) is highlighted. Remarkably, stereo-and chemoselectivities could be tuned by the cavity size of cyclodextrins, exploiting the relevance of host-guest interactions. UVVis experiments have led to strong evidence concerning an interplay between Pd(II) and a-HPCD, possibly ascribed to a reduction/stabilization effect of CDs. Unexpectedly, hydroarylation was the favored pathway with acrylonitrile which provided access to 3-phenylpropionitrile derivatives without usual hydride donors. Finally, determination of soluble PdA C H T U N G T R E N N U N G (0/II) via AAS enabled the definition of a predominant homogeneous mechanism in which TONs over 5000 were observed.

No abstract

No abstract

No abstract

No abstract