Access to N -Hydroxyisoindolinones by Superacid-Induced Reactons of N -Hydroxyphthalimide and their Catalytic Activity in Fluorene Oxidation

Key Points

• This research aims to explore the transformation of N-hydroxyphthalimide in superacids and evaluate the catalytic efficacy of the products in fluorene oxidation.
• Reactions of N-hydroxyphthalimide in triflic acid or FSO3H–SbF5 leading to ring expansion.
• Synthesis of 2-hydroxy-2′,7′-dimethylspiro[isoindoline-1,9′-xanthen]-3-one and N-hydroxyisoindolinone through ionic hydrogenation.
• Testing the catalytic properties of the synthesized compounds in fluorene oxidation using sodium chlorite.
• N-hydroxyisoindolinone exhibited superior catalytic activity in oxidizing fluorene to fluorenone compared to N-hydroxyphthalimide.
• The reaction condition optimized with sodium chlorite demonstrated significant yield improvement for the transformation.
• The findings suggest promising applications for N-hydroxyisoindolinones in organic synthesis.