title: Synthesis of a family of 3-alkyl- or 3-aryl-substituted 1,2-dihydroquinazolinium salts and their isomerization to 4-iminium-1,2,3,4-tetrahydroquinolines.
abstract: A straightforward synthesis of substituted 1,2-dihydroquinazolinium triflates (3) is reported by reaction of 2-imino-substituted anilines with a range of carbonyl compounds in the presence of triflic acid via intermediate iminium salts. Similar reactions with di- or trialdehydes and triflic acid give bis- or tris-(1,2-dihydroquinazolinium) salts. Some 4-methyl substituted 1,2-dihydroquinazolinium salts rearrange, under various conditions, to their corresponding 4-iminium-1,2,3,4-tetrahydroquinolinium isomers (7). Most of salts 3 derived from ketones are rather unstable, which prevents their isolation or full characterization. The crystal structures of various 3 and 7 salts have been determined.
authors.affiliation: Grupo de Química Organometálica, Departamento de Química Inorgánica, Universidad de Murcia, Apartado 4021, 30071, Murcia, Spain. jvs1@um.es
authors.forename: José
authors.initials: J
authors.lastname: Vicente
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Chicote
authors.forename: Antonio Jesús
authors.initials: AJ
authors.lastname: Martínez-Martínez
authors.forename: Delia
authors.initials: D
authors.lastname: Bautista
authors.forename: Peter G
authors.initials: PG
authors.lastname: Jones