title: Solvent-free enantioselective Friedländer condensation with wet 1,1'-binaphthalene-2,2'-diamine-derived prolinamides as organocatalysts.
abstract: Wet unsupported and supported 1,1'-binaphthalene-2,2'-diamine (BINAM) derived prolinamides are efficient organocatalysts under solvent-free conditions at room temperature to perform the synthesis of chiral tacrine analogues in good yields (up to 93%) and excellent enantioselectivies (up to 96%). The Friedländer reaction involved in this process takes place with several cyclohexanone derivatives and 2-aminoaromatic aldehydes, and it is compatible with the presence of either electron-withdrawing or electron-donating groups at the aromatic ring of the 2-aminoaryl aldehyde derivatives used as electrophiles. The reaction can be extended to cyclopentanone derivatives, affording a regioisomeric but separable mixture of products. The use of the wet silica gel supported organocatalyst, under solvent-free conditions, for this process led to the expected product (up to 87% enantiomeric excess), with its reuse being possible at least up to five times.
authors.affiliation: Departamento de Química Orgánica e Instituto de Síntesis Orgánica, Facultad de Ciencias, Universidad de Alicante, Apdo. 99, E-03080 Alicante, Spain.
authors.forename: Abraham
authors.initials: A
authors.lastname: Bañón-Caballero
authors.forename: Gabriela
authors.initials: G
authors.lastname: Guillena
authors.forename: Carmen
authors.initials: C
authors.lastname: Nájera
mesh_terms: D002384:Catalysis; D003959:Diamines / Q000737:chemistry*; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry*; D011392:Proline / Q000031:analogs & derivatives* / Q000737:chemistry; D013237:Stereoisomerism; D013619:Tacrine / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C500338:1,1'-binaphthyl-2,2'-diamine; D003959:Diamines; D009281:Naphthalenes; D013619:Tacrine; D011392:Proline; C056291:prolinamide