Proline and secondary amine co-catalyzed condensation of cyclobutanone with aldehydes: a facile access to 2-methylenecyclobutanones under near neutral conditions

Unraveling the Role of Supramolecular Additives in a Proline‐Catalyzed Reaction

“…To the best of our knowledge, there aren't other catalytic systems displaying a similar behavior and it is therefore a phenomenon worth exploring. Moreover, previous reports regarding the participation of other H‐bond donor species (Brønsted acids, water, alcohols, ureas, thioureas, thiouronium salts, imidazolium salts, secondary amines) as additives in proline‐promoted aldol reactions do not provide an insight on their mode of action. Filling up this gap would allow designing more effective cooperative catalyst/co‐catalyst systems, which are not very much understood, particularly on asymmetric catalysis .…”