scholarly journals Stereoselective synthesis of perillaldehyde-based chiral β-amino acid derivatives through conjugate addition of lithium amides

2014 ◽  
Vol 10 ◽  
pp. 2738-2742 ◽  
Author(s):  
Zsolt Szakonyi ◽  
Reijo Sillanpää ◽  
Ferenc Fülöp
Keyword(s):  
Amino Acids ◽  
Stereoselective Synthesis ◽  
Minor Component ◽  
Conjugate Addition ◽  
Building Blocks ◽  
Major Product ◽  
Amino Ester ◽  
Chiral Amine ◽  
Amino Esters ◽  
Lithium Amides

The Michael addition of dibenzylamine to (+)-tert-butyl perillate (3) and to (+)-tert-butyl phellandrate (6), derived from (S)-(−)-perillaldehyde (1), resulted in diastereomeric β-amino esters 7A–D in a moderately stereospecific reaction in a ratio of 76:17:6:1. After separation of the diastereoisomers, the major product, cis isomer 7A, was quantitatively isomerized to the minor component, trans-amino ester 7D. All four isomers were transformed to the corresponding β-amino acids 10A–D, which are promising building blocks for the synthesis of β-peptides and 1,3-heterocycles in three steps. The steric effects of the isopropyl group at position 4 and of the α-methyl substituent of (R)-N-benzyl-N-α-methylbenzylamine on the reactivity were also studied and, upon application of a chiral amine, excellent stereoselectivity of the conjugate addition was observed. Amino ester 11 was obtained as a single product and transformed to the corresponding amino acids 10A and 10D in good yields on the gram scale.

Stereoselective synthesis of pinane-based β- and γ-amino acids via conjugate addition of lithium amides and nitromethane

2010 ◽  
Vol 21 (20) ◽  
pp. 2498-2504 ◽  
Author(s):  
Zsolt Szakonyi ◽  
Árpád Balázs ◽  
Tamás A. Martinek ◽  
Ferenc Fülöp
Keyword(s):  
Amino Acids ◽  
Stereoselective Synthesis ◽  
Conjugate Addition ◽  
Lithium Amides

scholarly journals Constrained Dipeptide Surrogates: 5- and 7-Hydroxy Indolizidin-2-one Amino Acid Synthesis from Iodolactonization of Dehydro-2,8-diamino Azelates

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 67
Author(s):  
Ramakotaiah Mulamreddy ◽  
William D. Lubell
Keyword(s):  
Amino Acids ◽  
Acid Synthesis ◽  
Ring System ◽  
Dihedral Angles ◽  
Type Ii ◽  
Amino Ester ◽  
Amino Acid Synthesis ◽  
X Ray ◽  
Amino Esters ◽  
Peptide Mimicry

The constrained dipeptide surrogates 5- and 7-hydroxy indolizidin-2-one N-(Boc)amino acids have been synthesized from L-serine as a chiral educt. A linear precursor ∆4-unsaturated (2S,8S)-2,8-bis[N-(Boc)amino]azelic acid was prepared in five steps from L-serine. Although epoxidation and dihydroxylation pathways gave mixtures of hydroxy indolizidin-2-one diastereomers, iodolactonization of the ∆4-azelate stereoselectively delivered a lactone iodide from which separable (5S)- and (7S)-hydroxy indolizidin-2-one N-(Boc)amino esters were synthesized by sequences featuring intramolecular iodide displacement and lactam formation. X-ray analysis of the (7S)-hydroxy indolizidin-2-one N-(Boc)amino ester indicated that the backbone dihedral angles embedded in the bicyclic ring system resembled those of the central residues of an ideal type II’ β-turn indicating the potential for peptide mimicry.

Enantioselective Preparation of Alcohols and Amines: The Lam Synthesis of (+)-Tanikolide

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Amino Acids ◽  
Conjugate Addition ◽  
Allylic Alcohol ◽  
University Of Virginia ◽  
Chiral Amine ◽  
Aliphatic Aldehydes ◽  
Nucleophilic Rearrangement ◽  
Silyl Acetals ◽  
Institute Of Technology ◽  
The University

Takashi Ooi of Nagoya University effected (J. Am. Chem. Soc. 2010, 132, 12240) the enantioselective protonation of ketene silyl acetals such as 1 to give 2 in high ee. Hyeon-Kyu Lee of the Korean Research Institute of Chemical Technology achieved (Org. Lett. 2010, 12, 4184) high ee in the hydrogenation of the cyclic sulfamidate 3 to 4. Doo Ok Jang of Yonsei University combined (J. Am. Chem. Soc. 2010, 132, 12168) the nucleophilic allyl indium with a protonated chiral amine to effect homologation of 5 to 6. Ryo Shintani and Tamio Hayashi of Kyoto University reported (Org. Lett. 2010, 12, 4106) a related advance with tetraarylborates. Kazuaki Ishihara, also of Nagoya University (Org. Lett. 2010, 12, 3502) and Yoshihiro Sohtome and Kazuo Nagasawa of the Tokyo University of Agriculture and Technology (Angew. Chem. Int. Ed. 2010, 49, 9254) devised conditions for adding malonate to imines such as 7. Professors Shintani and Hayashi also employed (J. Am. Chem. Soc. 2010, 132, 13168) tetraarylborates to convert 9 to the α-quaternary amine 10. Professor Ooi (Angew. Chem. Int. Ed. 2010, 49, 5567) and Wanbin Zhang of Shanghai Jiao Tong University (J. Am. Chem. Soc. 2010, 132, 15939) prepared α-quaternary amino acids such as 12 by nucleophilic rearrangement of 11. Keiji Maruoka, also of Kyoto University, reported (J. Am. Chem. Soc. 2010, 132, 17074; not illustrated) a catalytic enantioselective conjugate addition approach to α-quaternary amines. Shuji Akai of the University of Shizuoka converted (Org. Lett. 2010, 12, 4900) the racemic allylic alcohol 13 to the enantiomerically enriched acetate 14 by combining V-catalyzed equilibration with lipase-catalyzed acylation. Toshiro Harada of the Kyoto Institute of Technology added (Org. Lett. 2010, 12, 5270) the alkenylboron 16 to the aldehyde 15 with high ee. Xiang Zhou of Wuhan University and Lin Pu of the University of Virginia significantly improved (Tetrahedron Lett . 2010, 51, 5024) a protocol for the enantioselective addition of aliphatic alkynes to aliphatic aldehydes. For other enantioselective additions to aldehydes (not illustrated), see J. Org. Chem. 2010, 75 , 5326 and Org. Lett. 2010, 12, 5088.

An Alternative Synthesis of Some Carbohydrate α-Amino Acids

2004 ◽  
Vol 57 (1) ◽  
pp. 25 ◽  
Author(s):  
Grant S. Forman ◽  
Adrian Scaffidi ◽  
Robert V. Stick
Keyword(s):  
Amino Acids ◽  
Sodium Azide ◽  
Subsequent Treatment ◽  
Amino Ester ◽  
Alternative Synthesis ◽  
Tertiary Alcohols ◽  
Amino Esters

Several carbohydrate ketones have been converted into their trichloromethyl-branched tertiary alcohols. A subsequent treatment of these alcohols under Corey–Link conditions (base, sodium azide, methanol) has given rise to α-azido esters, transformable into azido acids, amino esters, and amino acids. An amino ester and an azido acid have been coupled to form a dipeptide.

scholarly journals Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore

2020 ◽  
Vol 16 ◽  
pp. 1111-1123
Author(s):  
Esteban P Urriolabeitia ◽  
Pablo Sánchez ◽  
Alexandra Pop ◽  
Cristian Silvestru ◽  
Eduardo Laga ◽  
...  
Keyword(s):  
Amino Acids ◽  
Blue Light ◽  
Stereoselective Synthesis ◽  
Open Book ◽  
Face To Face ◽  
Amino Esters

The stereoselective synthesis of truxillic bis-amino esters from polyfunctional oxazolones is reported. The reaction of 4-((Z)-arylidene)-2-(E)-styryl-5(4H)-oxazolones 2 with Pd(OAc)2 resulted in ortho-palladation and the formation of a dinuclear open-book complexes 3 with carboxylate bridges, where the Pd atom is C^N bonded to the oxazolone. In 3 the two exocyclic C=C bonds of the oxazolone are in a face-to-face arrangement, which is optimal for their [2 + 2] photocycloaddition. Irradiation of dimers 3 in CH2Cl2 solution with blue light (465 nm) promoted the chemo- and stereoselective [2 + 2] photocycloaddition of the exocyclic C=C bonds and the formation of cyclobutane-containing ortho-palladated complexes 4. Treatment of 4 with CO in a MeOH/NCMe mixture promoted the methoxycarbonylation of the palladated carbon and the release of the corresponding ortho-functionalized 1,3-diaminotruxillic bis-amino esters 5 as single isomers.

scholarly journals Prebiotic synthesis of 2-deoxy-d-ribose from interstellar building blocks promoted by amino esters or amino nitriles

2017 ◽  
Vol 53 (75) ◽  
pp. 10362-10365 ◽  
Author(s):  
Andrew M. Steer ◽  
Nicolas Bia ◽  
David K. Smith ◽  
Paul A. Clarke
Keyword(s):  
Amino Acids ◽  
Prebiotic Synthesis ◽  
Building Blocks ◽  
Amino Esters ◽  
Interstellar Ices ◽  
Prebiotic Earth ◽  
Selective Formation

Amino esters and amino nitriles can promote the selective formation of 2-deoxy-d-ribose from materials present in interstellar ices. The use of amino nitriles suggests the possibility that carbohydrates may have existed before amino acids on the prebiotic Earth.

Stereoselective Synthesis of syn-γ-Hydroxynorvaline and Related α-Amino Acids

Synthesis ◽  
2019 ◽  
Vol 51 (24) ◽  
pp. 4568-4575 ◽  
Author(s):  
Dominika Valachová ◽  
Branislav Ferko ◽  
Eva Puchľová ◽  
Oľga Caletková ◽  
Dušan Berkeš ◽  
...  
Keyword(s):  
Amino Acids ◽  
Hplc Analysis ◽  
Stereoselective Synthesis ◽  
Glyoxylic Acid ◽  
Building Blocks ◽  
Enantiomeric Purity ◽  
Rapid Synthesis ◽  
Total Syntheses ◽  
Enantiomerically Pure ◽  
Target Molecules

The total syntheses of three enantiomerically pure non-proteinogenic amino acids, l-norvaline, γ-oxonorvaline, and syn-γ-hydroxynorvaline, are reported. The chromatography-free route pivoted on the construction of highly enantiomerically enriched substituted α-amino-γ-oxopentanoic acid, from which all three members were accessed divergently via chemoselective and stereoselective reductions. The rapid synthesis of this key α-amino-γ-oxopentanoic acid was achieved by a highly diastereoselective crystallisation-driven three-component Mannich reaction from the readily available building blocks acetone, glyoxylic acid monohydrate, and (S)-(4-methoxyphenyl)ethylamine. The enantiomeric purity of all target molecules was confirmed by HPLC analysis, either of the amino acids or their derivatives.

scholarly journals Homologated amino acids with three vicinal fluorines positioned along the backbone: development of a stereoselective synthesis

2017 ◽  
Vol 13 ◽  
pp. 2316-2325 ◽  
Author(s):  
Raju Cheerlavancha ◽  
Ahmed Ahmed ◽  
Yun Cheuk Leung ◽  
Aggie Lawer ◽  
Qing-Quan Liu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Stereoselective Synthesis ◽  
Building Blocks ◽  
Synthetic Approach ◽  
Potential Applications ◽  
Shape Controlled ◽  
Nucleophilic Fluorination

Backbone-extended amino acids have a variety of potential applications in peptide and protein science, particularly if the geometry of the amino acid is controllable. Here we describe the synthesis of δ-amino acids that contain three vicinal C–F bonds positioned along the backbone. The ultimately successful synthetic approach emerged through the investigation of several methods based on both electrophilic and nucleophilic fluorination chemistry. We show that different diastereoisomers of this fluorinated δ-amino acid adopt distinct conformations in solution, suggesting that these molecules might have value as shape-controlled building blocks for future applications in peptide science.

Exogenous Directing Group Free, Ligand-Enabled gamma-C(sp3)–H Arylation of Free Primary Aliphatic Amines and α-Amino Esters

2019 ◽  
Author(s):  
Yongzheng Ding ◽  
Shuai Fan ◽  
Xiaoxi Chen ◽  
yuzhen gao ◽  
Gang Li
Keyword(s):  
Amino Acids ◽  
Large Scale ◽  
Free Ligand ◽  
Aliphatic Amines ◽  
Rapid Synthesis ◽  
Amino Esters ◽  
Directing Group ◽  
Large Scale Synthesis ◽  
Primary Aliphatic Amines

A Pdᴵᴵ-catalyzed, ligand-enabled gamma-C(sp3)–H arylation of free primary aliphatic amines and amino esters without using an exogenous directing group is reported. This reaction is compatible with unhindered free aliphatic amines, and it is also be applicable to the rapid synthesis of biologically and synthetically valuable unnatural α-amino acids. Large scale synthesis is also feasible using this method.<br>

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