title: C2-Symmetric pyrrolidine-derived squaramides as recyclable organocatalysts for asymmetric Michael reactions.
abstract: Novel C2-symmetric N,N'-bis-[(pyrrolidin-2-yl)methyl-squaramide] TFA salts bearing (R,R)- or (S,S)-1,2-di(pyridin-2-yl)ethane spacer groups were synthesized and applied, in combination with TEA, as efficient organocatalysts for asymmetric reactions between cyclohexanone derivatives and β-nitrostyrenes to afford the corresponding Michael adducts in high yields with good to excellent enantioselectivity. The catalytic procedure is readily scalable and recyclable over four times without a negative impact on the selectivity of the reaction. Some of the prepared compounds are valuable precursors to useful bioactive molecules.
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, 119991 Moscow, Russia. zlotin@ioc.ac.ru.
authors.forename: A S
authors.initials: AS
authors.lastname: Kucherenko
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, 119991 Moscow, Russia. zlotin@ioc.ac.ru.
authors.forename: V G
authors.initials: VG
authors.lastname: Lisnyak
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, 119991 Moscow, Russia. zlotin@ioc.ac.ru and D. I. Mendeleev University of Chemical Technology, 9 Miusskaya Square, 125047 Moscow, Russia.
authors.forename: A A
authors.initials: AA
authors.lastname: Kostenko
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, 119991 Moscow, Russia. zlotin@ioc.ac.ru.
authors.forename: S V
authors.initials: SV
authors.lastname: Kochetkov
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, 119991 Moscow, Russia. zlotin@ioc.ac.ru.
authors.forename: S G
authors.initials: SG
authors.lastname: Zlotin
mesh_terms: D002384:Catalysis; D003512:Cyclohexanones / Q000737:chemistry; D011759:Pyrrolidines / Q000737:chemistry*; D011803:Quinine / Q000031:analogs & derivatives* / Q000737:chemistry; D020058:Styrene / Q000737:chemistry
chemical_list: D003512:Cyclohexanones; D011759:Pyrrolidines; C000609819:squaramide; D020058:Styrene; C036468:cyclohexanone; D011803:Quinine; C032519:pyrrolidine