title: Versatile and sustainable synthesis of cyclic imides from dicarboxylic acids and amines by Nb2O5 as a base-tolerant heterogeneous Lewis acid catalyst.
abstract: Catalytic condensation of dicarboxylics acid and amines without excess amount of activating reagents is the most atom-efficient but unprecedented synthetic method of cyclic imides. Here we present the first general catalytic method, proceeding selectively and efficiently in the presence of a commercial Nb2 O5 as a reusable and base-tolerant heterogeneous Lewis acid catalyst. The method is effective for the direct synthesis of pharmaceutically or industrially important cyclic imides, such as phensuximide, N-hydroxyphthalimide (NHPI), and unsubstituted cyclic imides from dicarboxylic acid or anhydrides with amines, hydroxylamine, or ammonia.
authors.affiliation: Catalysis Research Center, Hokkaido University, N-21, W-10, Sapporo 001-0021 (Japan), Fax: (+81) 11-706-9163.
authors.forename: Md Ayub
authors.initials: MA
authors.lastname: Ali
authors.forename: S M A Hakim
authors.initials: SM
authors.lastname: Siddiki
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kon
authors.forename: Junya
authors.initials: J
authors.lastname: Hasegawa
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D000588:Amines / Q000138:chemical synthesis*; D002384:Catalysis; D003998:Dicarboxylic Acids / Q000737:chemistry*; D007094:Imides / Q000138:chemical synthesis*; D058116:Lewis Acids / Q000737:chemistry; D008958:Models, Molecular; D009556:Niobium / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*
chemical_list: D000588:Amines; D003998:Dicarboxylic Acids; D007094:Imides; D058116:Lewis Acids; D010087:Oxides; D009556:Niobium; C073337:niobium pentoxide
keywords: Lewis acids; dicarboxylic acids; heterogeneous catalysis; imides; niobium oxides