N-Heterocyclic carbene catalyzed intramolecular crossed aldehyde–ketone benzoin condensation in the chalcone of o-phthalaldehyde: a facile synthesis of naphthalenones
The intramolecular crossedaldehyde–ketonebenzoin condensation in the chalcone of o-phthalaldehyde (OPA) catalyzed by N-heterocyclic carbene (NHCs) generated in situ from readily available imidazolium and thiazolium salts is described. In this reaction, bicyclic α-hydroxyl ketones (naphthalenone type tertiary alcohol) were selectively produced in good yields (75–94%) in shorter reaction times (20 min)