VIP (very important paper): The following paper is very important in the opinion of two referees.
«Identification of active surface species for Friedel-Crafts Acylation and Koch type carbonylation reactions by in situ solid state NMR spectroscopy»
by Inés Lezcano-González, José A. Vidal-Moya, Mercedes Boronat, Teresa Blasco*, and Avelino Corma has now been published online.
Finding the culprits: In situ NMR spectroscopy combined with theoretical calculations show the formation of acetyl species covalently bound to framework oxygen atoms in acid zeolites. These species, and not the usually assumed acylium cations, are the reactive intermediates in Friedel–Crafts acylation and Koch carbonylation reactions on zeolites.