boronic acid catalyzed intermolecular aza-Piancatelli rearrangement to access a wide range of trans-4,5-disubstituted cyclopentenones is described. The catalytic system can also be extended to intramolecular aza-Piancatelli rearrangement to afford a wide range of azaspirocycles. Good to excellent yields were obtained in an excellent diastereoselective manner. A first example of boronic acid catalyzed