title: Regioselective piperidine-catalyzed tandem imination-isocyanate annulation to fused tricyclic triazines.
abstract: A novel tandem imination-isocyanate-mediated annulation was explored. Ionic liquid-immobilized 2-aminobenzimidazoles react sequentially with aldehydes and isocyanates to give highly functionalized benzimidazole-embedded triazines. The second-stage transformation revealed that the formation of triazinone functionality is entirely regioselective to allow rapid assembly of biologically interesting tricyclic skeletons. In conjunction with the application of microwave irradiation and IL support, this method provides an efficient route to access substituted benzoimidazotriazines.
authors.affiliation: Department of Applied Chemistry, National Chiao Tung University , Hsinchu 300-10, Taiwan.
authors.forename: Indrajeet J
authors.initials: IJ
authors.lastname: Barve
authors.forename: Chih-Hau
authors.initials: CH
authors.lastname: Chen
authors.forename: Chih-Hsien
authors.initials: CH
authors.lastname: Kao
authors.forename: Chung-Ming
authors.initials: CM
authors.lastname: Sun
mesh_terms: D001562:Benzimidazoles / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D007097:Imines / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry; D017953:Isocyanates / Q000737:chemistry*; D008872:Microwaves; D008958:Models, Molecular; D010880:Piperidines / Q000737:chemistry*; D014227:Triazines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001562:Benzimidazoles; D007097:Imines; D052578:Ionic Liquids; D017953:Isocyanates; D010880:Piperidines; D014227:Triazines; C032727:piperidine
keywords: benzoimidazotriazine; imination; ionic liquid; isocyanate-mediated annulation; microwave; tandem reaction