研究了在固-液相转移催化条件下,通过烷基化,迈克尔加成和羰基加成以及甘氨酸和丙氨酸酯衍生的亚胺与苯甲醛环加成,合成短而温和高效的α-氨基酸的路线。固液相转移催化反应的关键是为各种反应物选择碱。产量取决于所用的碱。讨论了使用KOH,K 2 CO 3和Na 2 CO 3获得的结果。研究了固液PTC苄基化反应的动力学,我们提出了一种可能的固液PTC机理作为界面自动催化程序。介绍了一些α-氨基酸合成的细节。
A Concise Synthesis of Sterically Hindered 3-Amino-2-Oxindoles
作者:Stephen J. O’Connor、Zheng Liu
DOI:10.1055/s-2003-42074
日期:——
2-pyridylalanine as the aminoacid starting materials, while 3-pyridylalanine and O-methyltyrosine are less efficiently arylated. Sterically hindered aminoacids such as valine and phenylglycine are for all practical purposes, not substrates for the key nucleophilic substitution reaction. The resulting 3-alkyl-3-amino-2-oxindoles are important intermediates for the preparation of drug-like substances.
Catalytic asymmetric synthesis of diazabicyclo[3.1.0]hexanes by 1,3-dipolar cycloaddition of azomethine ylides with azirines
作者:Alba Molina、Sergio Díaz-Tendero、Javier Adrio、Juan C. Carretero
DOI:10.1039/d0cc01061h
日期:——
Substituted 1,3-diazabicyclo[3.1.0]hexanes with two contiguous quaternary stereocentres are readily prepared by catalytic asymmetric [3+2] cycloaddition of α-substituted iminoesters with azirines. High diastereoselectivities and enantioselectivities (up to 98% ee) are achieved using CuI/(R)-Fesulphos as the catalytic system.
The Catalysis and Asymmetric Induction of Chiral Reverse Micelle: Synthesis of Optically Active α-Amino Acids
作者:Peipei Sun、Yongmin Zhang
DOI:10.1080/00397919708005465
日期:1997.12
Abstract: Through alkylation of N-benzylideneglycine ethyl ester in chiral reverse micelle, followed by hydrolysis of the resulting products, optically active α-amino acids were synthesized.
α-Hydroxymethylation of Schiff Bases Derived from α-Amino Acid Esters
作者:Anna Calcagni、Domenico Rossi、Gino Lucente
DOI:10.1055/s-1981-29476
日期:——
Schiff Bases of Amino Acid Esters as New Substrates for the Enantioselective Enzymatic Hydrolysis and Accompanied Asymmetric Transformations in Aqueous Organic Solvents<sup>1</sup><sup>,</sup><sup>2</sup>
作者:Virinder S. Parmar、Amarjit Singh、Kirpal S. Bisht、Naresh Kumar、Y. N. Belokon、K. A. Kochetkov、N. S. Ikonnikov、S. A. Orlova、V. I. Tararov、T. F. Saveleva
DOI:10.1021/jo941734v
日期:1996.1.1
The enzyme (lipases and chymotrypsin)-catalyzed hydrolysis of Schiff bases derived from racemic amino acid esters and aromatic aldehydes has been investigated. The reactions were successfully carried out in different aqueous organic solvents at ambient temperature, but the aqueous acetonitrile (5.4% water content by volume) was the solvent of choice. The L-amino acid (ee 98%) precipitated out from the solution as the reaction progressed, and the liberated aldehyde and unhydrolyzed D-ester (ee 40-98%) remained in the solution. The range of substrates included amino acids having different types of side chains. The addition of an organic base (DABCO) into the solution resulted in the racemization of the remaining D-ester and the additional hydrolysis of the substrate, thus leading to the effective asymmetric transformation of the initial ester. Upto 87.5% of the initial racemate was converted into the L-enantiomer.