title: A highly enantioselective Mannich reaction of aldehydes with cyclic N-acyliminium ions by synergistic catalysis.
abstract: Matched combinations of Brønsted or Lewis acids with suitable pro-electrophiles and secondary amine organocatalysts enable the novel enantioselective syntheses of carbamoyl dihydroquinoline and tetrahydropyridine derivatives with concomitant formation of two stereocenters. A short formal asymmetric synthesis of (2R,2'R)-threo-methylphenidate (Ritalin) is also described.
authors.affiliation: Dipartimento di Farmacia, Sede di Chimica Bioorganica e Biofarmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy. pineschi@farm.unipi.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Berti
authors.forename: Federico
authors.initials: F
authors.lastname: Malossi
authors.forename: Fabio
authors.initials: F
authors.lastname: Marchetti
authors.forename: Mauro
authors.initials: M
authors.lastname: Pineschi
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D007097:Imines / Q000737:chemistry*; D007477:Ions; D008774:Methylphenidate / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D007097:Imines; D007477:Ions; D008774:Methylphenidate