Insights into the Friedel-Crafts Benzoylation of -Methylpyrrole inside the Confined Space of the Self-Assembled Resorcinarene Capsule.

Friedel-Crafts benzoylation of -methylpyrrole can run inside the confined space of the hexameric resorcinarene capsule . The bridged water molecules at the corner of act as H-bonding donor groups to polarize the C-Cl bond of benzoyl chlorides -. Confinement effects on the regiochemistry of the FC benzoylation of -methylpyrrole are observed. The nature of the -substituents of - and their ability to establish H-bonds with the water molecules of work synergistically with the steric constrictions imposed by the capsule to drive the regiochemistry of products -. QM investigations indicate that inside the cavity of , the FC benzoylation of has a bimolecular concerted S2 mechanism, appropriately, above-plane nucleophilic vinylic substitution (SVπ)─supported by H-bonding interactions between water molecules and both the leaving Cl atom and the carbonyl group.