953787-40-1Relevant academic research and scientific papers
Enantioselective synthesis of anti-β-substituted γ,δ- unsaturated amino acids: A highly selective asymmetric thio-Claisen rearrangement
Liu, Zhihua,Qu, Hongchang,Gu, Xuyuan,Min, Byoung J.,Nyberg, Joel,Hruby, Victor J.
supporting information; experimental part, p. 4105 - 4108 (2009/05/30)
(Chemical Equation Presented) A novel synthesis of optically active anti-β-substituted γ,δ-unsaturated amino acids via a thio-Claisen rearrangement has been achieved. A 2,5-diphenylpyrrolidine was used as a (C2-symmetric chiral auxiliary to control the stereochemistry, giving good yields and excellent diastereoselectivities and enantioselectivities.
Asymmetric eschenmoser-claisen rearrangement for anti-β-substituted γ,δ-unsaturated amino acids
Qu, Hongchang,Gu, Xuyuan,Liu, Zhihua,Min, Byoung J.,Hruby, Victor J.
, p. 3997 - 4000 (2008/02/11)
Optically active anti-β-substituted γ,δ-unsaturated amino acids are important synthetic building blocks in organic synthesis and for peptidomimetics. A novel asymmetric Eschenmoser-Claisen rearrangement with use of a C2-symmetric chiral auxiliary was developed to generate this type of amino acid. Excellent diastereoselectivities and high enantioselectivities (87-93% ee) were obtained after the chiral auxiliary was removed via iodolactonization/zinc reduction.
Synthesis of β-substituted α-amino acids with use of iridium-catalyzed asymmetric allylic substitution
Kanayama, Takatoshi,Yoshida, Kazumasa,Miyabe, Hideto,Kimachi, Tetsutaro,Takemoto, Yoshiji
, p. 6197 - 6201 (2007/10/03)
The asymmetric synthesis of β-substituted α-amino acids with use of iridium-catalyzed allylic substitution was described. The Ir-catalyzed allylic substitution of diphenylimino glycinate with allylic phosphates proceeded smoothly even at 0 °C and gave branch products with high enantioselectivity (up to 97% ee), when chiral bidentate phosphite bearing the 2-ethylthioethyl group was employed. In addition, both diastereomers of the branch products were synthesized stereoselectively by simply switching the base employed. These methods were also applied to the asymmetric synthesis of quaternary α-amino acids.
