RhII‐Catalyzed Cycloaddition of α‐Diazo Homophthalimides and Nitriles Delivers Oxazolo[5,4‐c]isoquinolin‐5(4H)‐one Scaffold

Homophthalimides underwent facile diazo transfer reactions and the resulting diazo homophthalimides entered cycloaddition reactions with nitriles catalyzed by Rh 2 (OAc) 4 . The latter reaction represents the first example of 1,3‐oxazole synthesis involving nitrile cycloaddition to an α‐diazocarbonyl moiety incorporated in a heterocyclic system. The resulting oxazolo[5,4‐ c ]isoquinolin‐5(4 H )‐one scaffold represents a hitherto not described structural analog of an important cluster of tricyclic ring systems for drug design.