Direct Synthesis of Cyclic Imides from Carboxylic Anhydrides and Amines by Nb2O5 as a Water‐Tolerant Lewis Acid Catalyst. Issue 5 (4th February 2016)

• Record Type: Journal Article
• Authors: Ali, Md. A.; Moromi, Sondomoyee K.; Touchy, Abeda S.; Shimizu, Ken‐ichi
• Is Part Of: ChemCatChem. Volume 8:Issue 5(2016)
• Page Start: 891
• Page End: 894
• Publication Date: 2016-02-04
• Subjects: amination -- ketones -- Lewis acids -- niobium -- primary amines; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.201501172
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: In the 20 types of heterogeneous and homogenous catalysts screened, Nb2 O5 showed the highest activity for the synthesis of N ‐phenylsuccinimide by dehydrative condensation of succinic anhydride and aniline. Nb2 O5 was used in the direct imidation of a wide range of carboxylic anhydrides with NH3 or amines with various functional groups and could be reused. Kinetic studies showed that the Lewis acid Nb2 O5 catalyst was more water tolerant than both the Lewis acidic oxide TiO2 and the homogeneous Lewis acid ZrCl4, which resulted in higher yields of imides through the use of Nb2 O5 . Abstract : Int‐imidation tactics : A general method for the direct synthesis of cyclic imides from cyclic anhydrides with amines (or ammonia) under solvent‐free conditions is reported. Kinetic studies indicate that the Lewis acid sites of Nb2 O5 are highly water tolerant, which results in high catalytic activity for imidation even in the presence of water formed during the reaction. The catalyst can be recovered and reused four times without a marked decrease in yield.