63658-16-2Relevant academic research and scientific papers
Catalytic, contra-Thermodynamic Positional Alkene Isomerization
Occhialini, Gino,Palani, Vignesh,Wendlandt, Alison E.
supporting information, p. 145 - 152 (2022/01/19)
The positional isomerization of C═C double bonds is a powerful strategy for the interconversion of alkene regioisomers. However, existing methods provide access to thermodynamically more stable isomers from less stable starting materials. Here, we report
SUBSTITUTED HETEROCYCLICS WITH THERAPEUTIC ACTIVITY IN HIV
-
, (2021/05/29)
Substituted heterocyclic substituted pyrrole carboxamide compounds such as those represented by Formula I or Formula II are provided herein. Such compounds, or pharmaceutically acceptable salts thereof, can be used in the treatment of HIV infection and re
Preclinical Optimization of gp120 Entry Antagonists as anti-HIV-1 Agents with Improved Cytotoxicity and ADME Properties through Rational Design, Synthesis, and Antiviral Evaluation
Curreli, Francesca,Ahmed, Shahad,Benedict Victor, Sofia M.,Iusupov, Ildar R.,Belov, Dmitry S.,Markov, Pavel O.,Kurkin, Alexander V.,Altieri, Andrea,Debnath, Asim K.
, p. 1724 - 1749 (2020/03/10)
We previously reported a milestone in the optimization of NBD-11021, an HIV-1 gp120 antagonist, by developing a new and novel analogue, NBD-14189 (Ref1), which showed antiviral activity against HIV-1HXB2, with a half maximal inhibitory concentr
Facile access to α,β-dehydroalanine and α,β-dehydroamino butyric acid derivatives from DL-serines and threonines
Yang, Yong-Qing,Ji, Meng-Chen,Lu, Zheng,Jiang, Mao,Huang, Wei-Wei,He, Xue-Zhi
supporting information, p. 977 - 982 (2016/07/12)
ABSTRACT: Not only α,β-dehydroamino acids are important constituents for a number of bioactive peptides in nature, but also they are important building blocks for a variety of synthetic amino acids in organic synthesis. Methods to prepare dehydroamino aci
Npys-Mediated Elimination Reactions of Alcohols and Thiols: A Facile Route to Dehydroalanine and Dehydrobutyrine Building Blocks
Olsen, Frank N.,Tsakos, Michail,Poulsen, Thomas B.
supporting information, p. 2697 - 2701 (2015/11/27)
We report a new and rapid method for side-chain dehydration/dehydrothiolation of serine, threonine, and cysteine building blocks. The method relies on activation with 3-nitro-2-pyridinesulfenyl chloride (Npys-Cl) followed by treatment with base. It is pos
Synthesis of new β-amidodehydroaminobutyric acid derivatives and of new tyrosine derivatives using copper catalyzed C-N and C-O coupling reactions
Pereira,Vilaca,Ferreira
, p. 335 - 344 (2013/07/05)
Several β-amidodehydroaminobutyric acid derivatives were prepared from N,C-diprotected β-bromodehydroaminobutyric acids and amides by a copper catalyzed C-N coupling reaction. The best reaction conditions include the use of a catalytic amount of CuI, N,N'-dimethylethylenediamine as ligand and K 2CO3 as base in toluene at 110 C. The stereochemistry of the products was determined using NOE difference experiments and the results obtained are in agreement with an E-stereochemistry. Thus, the stereochemistry is maintained in the case of the E-isomers of β-bromodehydroaminobutyric acid derivatives, but when the Z-isomers were used as substrates the reaction proceeds with inversion of configuration. The use of β- bromodehydrodipeptides as substrates was also tested. It was found that the reaction outcome depend on the stereochemistry of the β- bromodehydrodipeptide and on the nature of the first amino acid residue. The products isolated were the β-amidodehydrodipeptide derivatives and/or the corresponding dihydropyrazines. The same catalytic system (CuI/N,N'- dimethylethylene diamine) was used in the C-O coupling reactions between a tyrosine derivative and aryl bromides. The new O-aryltyrosine derivatives were isolated in moderate to good yields. The photophysical properties of two of these compounds were studied in four solvents of different polarity. The results show that these compounds after deprotection can be used as fluorescence markers.
Synthesis and electrochemical behaviour of β-halodehydroamino acid derivatives
Ferreira, Paula M. T.,Monteiro,Pereira
experimental part, p. 499 - 513 (2010/11/04)
Several new β,β-dihalo and β-halo-β-substituted dehydroalanines and dehydrodipeptides were synthesized by reacting the corresponding dehydroamino acid derivative with a N-halosuccinimide or in the case of β,β-di-iododehydroalanines with iodine. The results obtained confirmed that the stereochemical outcome of the halogenation reaction with β-substituted dehydroamino acids depends on the substrate. Thus, an increase Z-stereoselectivity was found when the β-phenyldehydroalanines were used as substrates and when these compounds were N-protected with 4-tolylsulfonyl or with carbamates. From this study, it is also possible to conclude that when N-iodosuccinimide was used as reagent a much higher Z-stereoselectivity is found. The electrochemical behaviour of the halogenated dehydroamino acids was studied by cyclic voltammetry. The results show a shift in the reduction peak to higher potentials of the β-halogenated dehydroamino acids when compared with the corresponding non-halogenated derivatives. As expected, the β,β-dihalodehydroalanines exhibit higher peak potentials than β-halo-β-substituted dehydroalanines and the bromo derivatives have lower peak potentials when compared with the corresponding iododehydroamino acids. Controlled potential electrolysis of several β-halo-β-substituted dehydroamino acids afforded the corresponding dehalogenated dehydroamino acids as mixtures of their E and Z-isomers. In all cases, the major isomer isolated results from dehalogenation without isomerization. These new results show that electrochemical reduction constitutes a valuable method for the synthesis of the E-isomer of β-substituted dehydroalanines. Springer-Verlag 2010.
An improved procedure for the synthesis of dehydroamino acids and dehydropeptides from the carbonate derivatives of serine and threonine using tetrabutylammonium fluoride
Ramapanicker, Ramesh,Mishra, Roli,Chandrasekaran, Srinivasan
experimental part, p. 123 - 125 (2011/02/24)
Dehydroamino acids are important precursors for the synthesis of a number of unnatural amino acids and are structural components in many biologically active peptide derivatives. However, efficient synthetic procedures for their production in large amounts
Stereoselective syntheses of (E)-α,β-didehydroamino acid and peptide containing its residue utilizing oxazolidinone derivative
Kometani, Miki,Ihara, Kohki,Kimura, Rumi,Kinoshita, Hideki
experimental part, p. 364 - 380 (2009/06/28)
Reaction of methyl N-Boc-N-phenoxycarbonylglycinate with various aldehydes afforded the corresponding cis-4,5-oxazolidinone derivatives, which were effectively converted to (E)-α,β-didehydroamino acids by means of a base. Furthermore, N-deprotection of the oxazolidinone derivatives and subsequent coupling reaction with Boc-amino acid furnished the corresponding dipeptides, which were transformed to dipeptide containing α,α- didehydroamino acid with high E selectivity.
Reactivity of dehydroamino acids and dehydrodipeptides towards N- bromosuccinimide: Synthesis of β-bromo- and β,β- dibromodehydroamino acid derivatives and of substituted 4-imidazolidinones
Ferreira, Paula M. T.,Monteiro, Luis S.,Pereira, Goreti,Ribeiro, Liliana,Sacramento, Joana,Silva, Liseta
, p. 5934 - 5949 (2008/09/17)
We have developed a modification of our previously reported high-yielding method for the synthesis of N,N-diacyldehydroamino acid derivatives to prepare N-monoprotected dehydroamino acids and dehydrodipeptides. Thus, several dehydroalanine, dehydroaminobutyric acid and dehydrophenylalanine derivatives have been prepared by treating the corresponding L-serine, L-threonine and D,L-3-phenylserine (threo-type) derivatives with 1 equiv. of di-tert-butyl dicarbonate and 4-(dimethylamino)pyridine. The reaction proceeded with the initial formation of an O-tert-butyl carbonate which, by treament with N,N,N′,N′-tetramethylguanidine, underwent β elimination to give the corresponding dehydroamino acid derivative. This two-step method can be carried out as a one-pot procedure and is stereoselective, giving only the Z isomer. The N-monoprotected dehydroamino acids were treated with N-bromosuccinimide and thereafter with triethylamine to afford several β,β-dibromodehydroalanines or β-bromo-, β-alkyl- or β-aryldehydroalanines. The latter were obtained as mixtures of E and Z isomers. An increased stereoselectivity towards the formation of the Z isomer was observed with dehydrophenylalanine and when 4-tolylsulfonyl was used as the N-protecting group. In the case of dehydrodipeptides, the reaction with NBS and triethylamine afforded the corresponding brominated dehydrodipeptides when the N-protecting group was other than 4-tolylsulfonyl. However, when the reagent was a peptide with a dehydroamino acid as the second residue and an N-(4-tolylsulfonyl) group the corresponding 2,2-disubstituted 1-(4-tolylsulfonyl)imidazolidin-4-ones were obtained in good-to-high yields. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
