Enantioface-differentiating (Asymmetric) Hydrogenation of Keto Ester with Modified Nickel Catalyst. XXXII. Structural Requirements of Modifying Reagent and Substrate
作者:Shinji Okamoto、Tadao Harada、Akira Tai
DOI:10.1246/bcsj.52.2670
日期:1979.9
The enantioface-differentiating hydrogenation of α-, β-, γ-, and δ-keto esters over α-, β-, and γ-amino acid–MRNi has been conducted. The optimum enantio-differentiating power of α-amino acid-MRNi has been found in the hydrogenation of the β-keto ester and that of β-amino acid-MRNi found in the hydrogenation of the γ-keto ester. The results have been explained in terms of the intermolecular recognition between substrate and modifying reagent through the functional groups.
β2-Homo-Amino Acid Scan of µ-Selective Opioid Tetrapeptide TAPP
作者:Dagmara Tymecka、Piotr F. J. Lipiński、Piotr Kosson、Aleksandra Misicka
DOI:10.3390/molecules25102461
日期:——
included compounds in which a (R)- or (S)-β2-Homo-Homologue replaced the amino acids in the TAPP sequence. The derivatives with (R)- or (S)-β2hPhe4 turned out to bind µOR with affinities equal to that of the parent. β2hAAs in position 1 and 3 resulted in rather large affinity decreases, but the change differed depending on the stereochemistry. β2-Homologation in the second position gave derivatives with very
Catalytic Asymmetric Synthesis of Unprotected β<sup>2</sup>-Amino Acids
作者:Chendan Zhu、Francesca Mandrelli、Hui Zhou、Rajat Maji、Benjamin List
DOI:10.1021/jacs.1c00249
日期:2021.3.10
Importantly, both aromatic and aliphatic β2-amino acids can be obtained using this method. Mechanistic studies are consistent with the aminomethylation to proceed via silylium-based asymmetriccounteranion-directedcatalysis (Si-ACDC) and a transition state to explain the enantioselectivity is suggested on the basis of density functional theory calculation.
Enantioselective synthesis of β-amino acids. 7. Preparation of enantiopure α-substituted β-amino acids from 1-benzoyl-2(S)-tert-butyl-3-methylperhydropyrimidin-4-one.1,2
Inexpensive natural α-amino acid L-asparagine was efficiently converted to either (R)- or (S)-α-alkylated β-amino acids in enantiomerically pure state. The key intermediate in this protocol is the enantiopure N,N-acetal pyrimidinone (S)-1, a masked chiral derivative of β-alanine.
Deaminative and Decarboxylative Catalytic Alkylation of Amino Acids with Ketones
作者:Nishantha Kalutharage、Chae S. Yi
DOI:10.1002/anie.201307766
日期:2013.12.16
It cuts two ways: The cationic [Ru‐H] complex catalyzesselective coupling of α‐ and β‐amino acids with ketones to form α‐alkylated ketone products. The reaction involves CC and CNbondcleavage which result in regio‐ and stereoselective alkylation using amino acids. A broad substrate scope and high functional‐group tolerance is demonstrated.
它有两种切割方式:阳离子 [Ru-H] 络合物催化 α- 和 β- 氨基酸与酮的选择性偶联,形成 α-烷基化的酮产物。该反应涉及 C C 和 C N 键断裂,导致使用氨基酸进行区域和立体选择性烷基化。证明了广泛的底物范围和高官能团耐受性。