C3-symmetricchiraltrisimidazoline was designed and synthesized as a new entry of organocatalyst with the concept of constructing C3-symmetric molecules with three C2-symmetric chiral components, and the application of this novel catalyst to asymmetric conjugate addition of β-ketoesters to nitroolefins was described.
Direct Enantioselective Three-Component Kabachnik-Fields Reaction Catalyzed by Chiral Bis(imidazoline)-Zinc(II) Catalysts
作者:Mutsuyo Ohara、Shuichi Nakamura、Norio Shibata
DOI:10.1002/adsc.201100482
日期:2011.12
A direct three-component reaction of aldehydes, amines and diaryl phosphites was catalyzed by a zinc(II) complex of 1,3-bis(imidazolin-2-ly)pyridine (pybim) giving the corresponding α-aminophosphonates in good yield with good enantioselectivity. The reaction was applied to a wide variety of aromatic aldehydes to give products with excellent yields (up to 99%) and enantiomeric excesses (up to 93% ee)
The reaction of aromatic dialdehydes with enantiopure 1,2-diamines: an expeditious route to enantiopure tricyclic amidines
作者:D. Christopher Braddock、Thaïs Cailleau、Gemma Cansell、Stephen A. Hermitage、Rebecca H. Pouwer、Joanna M. Redmond、Andrew J.P. White
DOI:10.1016/j.tetasy.2010.12.002
日期:2010.12
The condensation of enantiopure 1,2-diamines with terephthalaldehyde, isophthalaldehyde or 2-iodo-, 2-alkyl- or 2-aryl-1,3-benzenedialdehydes in toluene followed by treatment with NBS in dichloromethane gives direct access to enantiopure 1,4-, and 1,3-di(4,5-dihydro-1H-imidazol-2-yl)benzenes (diamidines). The condensation of o-phthalaldehyde, and other ortho-disubstituted aromatic dialdehydes, with enantiopure 1,2-diamines, without NBS, gives enantiopure 3,5-dihydro-2H-imidazol-[2,1]-isoindoles. (C) 2010 Elsevier Ltd. All rights reserved.