title: Novel syntheses of enantiopure hexahydroimidazo[1,5-b]isoquinolines and tetrahydroimidazo[1,5-b]isoquinolin-1(5H)-ones via iminium cation cyclizations.
abstract: Condensations of chiral diamines 11a-c with benzotriazole and formaldehyde gave benzotriazolyl intermediates 12a-c; similar condensations of alpha-amino-amides 10a-c with benzotriazole and paraformaldehyde gave 14a-c. Subsequent treatment of 12a-c and 14a-c with AlCl(3) led to enantiopure tricyclic 1,2,3,5,10,10a-hexahydroimidazo[1,5-b]isoquinolines 1a-c and 2,3,10,10a-tetrahydroimidazo[1,5-b]isoquinolin-1(5H)-ones 15a-c, respectively, via Lewis acid promoted iminium cation cyclizations.
authors.affiliation: Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA. katritzky@chem.ufl.edu
authors.forename: Alan R
authors.initials: AR
authors.lastname: Katritzky
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Suzuki
authors.forename: Hai-Ying
authors.initials: HY
authors.lastname: He
mesh_terms: D003500:Cyclization; D007097:Imines; D018836:Inflammation Mediators / Q000138:chemical synthesis; D007546:Isoquinolines / Q000138:chemical synthesis*; D013237:Stereoisomerism
chemical_list: D007097:Imines; D018836:Inflammation Mediators; D007546:Isoquinolines