title: Face-selective addition to a cation-pi complex of a pyridinium salt: synthesis of chiral 1,4-dihydropyridines.
abstract: Selective shielding of one side of the pyridinium face by way of intramolecular cation-pi complex formation enabled nucleophiles to attack only from the non-shielded side, and consequently, chiral 1,4-dihydropyridines were produced stereoselectively with up to 99% de. The structure of the cation-pi complex was elucidated by 1H NMR studies and X-ray analysis.
authors.affiliation: Department of Chemistry, Faculty of Science, Ochanomizu University, Bunkyo-ku, Tokyo 112-8610, Japan. yamada@cc.ocha.ac.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Yamada
authors.forename: Chisako
authors.initials: C
authors.lastname: Morita
mesh_terms: D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D004095:Dihydropyridines / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D011726:Pyridinium Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D002412:Cations; D004095:Dihydropyridines; D011726:Pyridinium Compounds; C038806:1,4-dihydropyridine