Straightforward access to complex isoindolinones from the Ugi reaction of o-nitrobenzoic acid derivatives

The Ugi reaction of 2-nitrobenzoic acid derivatives has been used for a diversity oriented synthesis of complex isoindolinones via a SNAr reaction involving the peptidyl position. When the cyclization is triggered by strong bases such as potassium tert-butylate, the SNAr reaction is followed by a deamidification/oxidation sequence leading to 2-hydroxyisoindolinones. The latter may be further transformed into polycyclic fused isoindolinones via Pictet-Spengler type cyclization or O-alkylation/metathesis sequences.