Catalytic Enantioselective [3 + 2] Cycloaddition of α-Keto Ester Enolates and Nitrile Oxides
作者:Samuel L. Bartlett、Yoshihiro Sohtome、Daisuke Hashizume、Peter S. White、Miki Sawamura、Jeffrey S. Johnson、Mikiko Sodeoka
DOI:10.1021/jacs.7b03782
日期:2017.6.28
An enantioselective [3 + 2] cycloaddition reaction between nitrileoxides and transiently generated enolates of α-keto esters has been developed. The catalyst system was found to be compatible with in situ nitrile oxide-generation conditions. A versatile array of nitrileoxides and α-keto esters could participate in the cycloaddition, providing novel 5-hydroxy-2-isoxazolines in high chemical yield
Reaction design in asymmetric catalysis has traditionally been predicated on a structurally robust scaffold in both substrates and catalysts, to reduce the number of possible diastereomeric transition states. Herein, we present the stereochemical dynamics in the Ni(II)-catalyzed diastereoconvergent (3 + 2) cycloadditions of isomerizable nitrile-conjugated nitrones with α-ketoesterenolates. Even in
Organocatalytic Asymmetric Biomimetic Transamination: From α-Keto Esters to Optically Active α-Amino Acid Derivatives
作者:Xiao Xiao、Ying Xie、Cunxiang Su、Mao Liu、Yian Shi
DOI:10.1021/ja203138q
日期:2011.8.24
This paper describes an effective chiral base-catalyzed biomimetic transamination of α-ketoesters using simple benzyl amines. A wide variety of α-amino esters containing various functional groups can be synthesized in high enantioselectivity and reasonable yield.
Stereochemical Control in Microbial Reduction. 30. Reduction of Alkyl 2-Oxo-4-phenylbutyrate as Precursors of Angiotensin Converting Enzyme (ACE) Inhibitors
作者:Duc Hai Dao、Yasushi Kawai、Kouichi Hida、Sander Hornes、Kaoru Nakamura、Atsuyoshi Ohno、Mutsuo Okamura、Takeshi Akasaka
DOI:10.1246/bcsj.71.425
日期:1998.2
corresponding alkyl (R)-2-hydroxy-4-phenylbutyrates, versatile chiral buildingblocks in organic synthesis, in high chemical yield (80—90%) with excellent stereoselectivity ( > 90%ee). The reaction has been run in aqueous diethyl ether at 30 °C for 24 h under the catalysis of bakers’ yeast (Saccharomyces cerevisiae) which was preincubated for 6 h in the presence of phenacyl chloride. The amount of
Bi(OAc)<sub>3</sub>/Chiral Phosphoric Acid-Catalyzed Enantioselective 1,2- and Formal 1,4-Allylation Reaction of β,γ-Unsaturated α-Ketoesters
作者:Xiang-Shuai Liu、Yao Li、Xin Li
DOI:10.1021/acs.orglett.1c03453
日期:2021.12.3
highly efficient asymmetric 1,2-allylation reaction of β,γ-unsaturatedα-ketoesters was realized by using a Bi(OAc)3/chiral phosphoric acid catalyst system under mild conditions. Meanwhile, using this combined strategy of enantioselective 1,2-allylation and subsequent anionic oxy-Cope rearrangement, the asymmetric formal 1,4-allylation reaction was achieved by a one-pot process. These reactions offer