139255-92-8Relevant academic research and scientific papers
Organocatalytic asymmetric conjugate addition of nitroalkanes to α,β-unsaturated enones using novel imidazoline catalysts
Halland, Nis,Hazell, Rita G.,Jorgensen, Karl Anker
, p. 8331 - 8338 (2007/10/03)
A new catalytic enantioselective conjugate addition of nitroalkanes to acyclic α,β-unsaturated enones catalyzed by novel organic catalysts has been developed. A series of chiral amines has been tested as catalysts for the addition of 2-nitropropane to benzylideneacetone, and it is found that a novel imidazoline catalyst, prepared from phenylalanine, can catalyze a highly enantioselective 1,4addition reaction. The reaction of various acyclic and cyclic nitroalkanes was found to proceed well with enantioselectivities up to 86% ee, and enantiopure products can be obtained by recrystallization. The potential of the reaction is documented by the reaction of a series of substituted α,β-unsaturated enones with different nitroalkanes. Furthermore, the synthetic applicability of the reaction is demonstrated by the formation of optically active functionalized pyrrolines and pyrrolidines by reductive amination of the products. On the basis of the absolute configuration of the conjugate addition products, the mechanism for the reaction is discussed and a transition state proposed.
New chiral auxiliaries based on conformation control, a C2-symmetric 2,2-dimethylimidazolidine and 4-chiral 2,2-dialkyloxazolidines. Synthesis and conformational analysis of acrylamide derivatives
Kanemasa,Onimura
, p. 8631 - 8644 (2007/10/02)
New chirality-controlling auxiliaries, a C2-symmetric 2,2-dimethylimidazolidine and 4-chiral 2,2-dialkyloxazolidines, are readily prepared from a C2-symmetric 1,2-ethanediamine and naturally occurring α-amino acids, respectively. Con
2,2-dimethyl-4-phenyloxazolidine and 2,2-dimethyl-4,5-diphenylimidazolidine as new chiral auxiliaries. Applications to asymmetric nitrile oxide cycloadditions
Kanemasa,Onimura,Wada,Tanaka
, p. 1185 - 1188 (2007/10/02)
Asymmetric dipolar cycloadditions of a nitrile oxide to the acrylamide derivatives of two new chiral auxiliaries, (R)-2,2-dimethyl-4-phenyloxazolidines and (S,S)-2,2-dimethyl-4,5-diphenylimidazolidine, show satisfactorily high diastereoselectivities (up to 91%).
