6306-54-3Relevant academic research and scientific papers
Palladium-Catalyzed Decarbonylation of Amino Acid Derivatives via C-C Bond and C-N Bond Dual Activations
Deng, Gongtao,Jiang, Yaojia,Jiao, Yongjuan,Li, Yingmei,Wu, Jiamin,Zhang, Jinli,Zhang, Zhengyu
, p. 17462 - 17470 (2021/12/02)
A unique decarbonylation of an amino acid derivative catalytic system has been established via palladium-catalyzed C-C bond and C-N bond dual activations. By employing 8-aminoquinoline as the directing group, this transformation has been found to facilitate the high chemoselectivity to decarbonylation of amino acid derivatives rather than intramolecular deamination or cross-dehydrogenative coupling reactions. This method provides a straightforward avenue for constructing diverse functionalized amide compounds in good to excellent yields. We proposed a possible reaction pathway that may go through the C-C bond and C-N bond dual activations on the basis of the mechanistic studies.
Synthesis of new amides based on N-Phthaloyl-α-Amino Acids
Tukhtaev,Yusupov,Vinogradova
, p. 3049 - 3058 (2021/05/28)
N-phthaloyl derivatives of aliphatic α-amino acids were synthesized using phthalanhydride under standard conditions. The optimization reaction carried out by the thermal method to obtain the amides of these N-phthaloyl amino acids resulted in transimitted rather than amidation. The target amides of N-phthaloyl-α-amino acids were obtained by acylation of the amine with the corresponding acid chloroanhydrides in dichloromethane. These results were compared with the results of a similar acylation in a non-polar solvent (benzene). The dependence of the direction of the reaction on the duration of the acylation and the amount of amine used was established. The conditions for the formation of the corresponding N-phthaloyl-α-amino acid amides and asymmetric phthalic acid diamides were found. It is noteworthy that the formation of diamides is directly proportional to the equivalent amount of amine and the duration of the reaction, which makes it possible to purposefully control the synthesis in one reactor.
General Access to Modified α-Amino Acids by Bioinspired Stereoselective γ-C?H Bond Lactonization
Vicens, Laia,Bietti, Massimo,Costas, Miquel
supporting information, p. 4740 - 4746 (2020/12/25)
α-Amino acids represent a valuable class of natural products employed as building blocks in biological and chemical synthesis. Because of the limited number of natural amino acids available, and of their widespread application in proteomics, diagnosis, drug delivery and catalysis, there is an increasing demand for the development of procedures for the preparation of modified analogues. Herein, we show that the use of bioinspired manganese catalysts and H2O2 under mild conditions, provides access to modified α-amino acids via γ-C?H bond lactonization. The system can efficiently target 1°, 2° and 3° γ-C?H bonds of α-substituted and achiral α,α-disubstituted α-amino acids with outstanding site-selectivity, good to excellent diastereoselectivity and (where applicable) enantioselectivity. This methodology may be considered alternative to well-established organometallic procedures.
A Novel Class of 7-Membered Heterocyclic Compounds
Bauer, Adriano,Borsos, Eszter,Maulide, Nuno
supporting information, p. 3971 - 3974 (2020/05/25)
The work presented herein describes the synthesis of a formerly inaccessible class of heterocyclic compounds. The reaction relies on α-phthalimido-amides, which are readily prepared from amino acids in 2 simple reactions steps. Under amide activation conditions in which classical keteniminium ions are not formed, the nitrile solvent is incorporated into the new fused 7-membered ring system. Due to the absence of a keteniminium intermediate, the stereogenic information in the α-position is fully retained.
Tetrasubstituted Furans by Nucleophile-Induced Cleavage of Carbonyl Ylide-DMAD Cycloadducts
Dobesch, Matthias,Greiner, Julian,Maas, Gerhard
, p. 2987 - 3000 (2020/08/10)
Compounds incorporating a 4-aza-8-oxabicyclo[3.2.1]oct-6-en-2-one moiety, which were prepared by a tandem carbenoid carbonyl ylide cyclization/[3+2]-cycloaddition reaction from ethyl 2-diazo-3-oxo-4-phthalimidobutanoates, undergo a nucleophile-induced two-bond ring cleavage when treated with protic heteronucleophiles. In this manner, tetrasubstituted furantricarboxylates, tethered with α-amino acids, esters, thioesters, and amides by a 2-carbonylphenyl moiety, are obtained.
AMINO ACID DERIVATIVES FOR THE TREATMENT OF INFLAMMATORY DISEASES
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Page/Page column 33, (2020/08/13)
The present disclosure provides certain amino acid derivatives that inhibit NF-kB activation and are therefore useful for the treatment of inflammatory diseases. Also provided are pharmaceutical compositions containing such compounds and processes for preparing such compounds.
Electrochemical C(sp 3)-H Fluorination
Baran, Phil S.,Chen, Longrui,Chen, Miao,Hoshikawa, Tamaki,Kawamata, Yu,Li, Chao,Mykhailiuk, Pavel,Nakamura, Hugh,Peters, Byron K.,Reisberg, Solomon H.,Shibuguchi, Tomoyuki,Takahira, Yusuke
supporting information, p. 1178 - 1182 (2019/06/08)
A simple and robust method for electrochemical alkyl C-H fluorination is presented. Using a simple nitrate additive, a widely available fluorine source (Selectfluor), and carbon-based electrodes, a wide variety of activated and unactivated C-H bonds are converted into their C-F congeners. The scalability of the reaction is also demonstrated with a 100 gram preparation of fluorovaline.
Efficient Kinetic Resolution of Sulfur-Stereogenic Sulfoximines by Exploiting CpXRhIII-Catalyzed C?H Functionalization
Brauns, Marcus,Cramer, Nicolai
supporting information, p. 8902 - 8906 (2019/06/04)
Chiral sulfoximines with stereogenic sulfur atoms are promising motifs in drug discovery. We report an efficient method to access chiral sulfoximines through a C?H functionalization based kinetic resolution. A rhodium(III) complex equipped with a chiral Cpx ligand selectively participates in conjunction with phthaloyl phenylalanine in the C?H activation of just one of the two sulfoximine enantiomers. The intermediate reacts with various diazo compounds, providing access to chiral 1,2-benzothiazines with synthetically valuable substitution patterns. Both sulfoximines and 1,2-benzothiazines were obtained in high yields and excellent enantioselectivity, with s-values of up to 200. The utility of the method is illustrated by the synthesis of the key intermediates of two pharmacologically relevant kinase inhibitors.
Amino acid chiral ligand containing bidentate coordination group, chiral catalyst, and corresponding preparation methods and applications thereof
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Paragraph 0073, (2019/10/02)
The present invention relates to an amino acid chiral ligand containing a bidentate coordination group, a chiral catalyst, and corresponding preparation methods and applications thereof. The chiral ligand is prepared from a cheap and easily available amino acid, and the development of the chiral ligand can improve the diversity of the chiral ligand. The chiral Ir (III) catalyst is simply and efficiently prepared from the chiral ligand only through a one-step reaction. The chiral Ir (III) catalyst is characterized in that a bidentate guiding group is introduced to an amino acid framework to change the original coordination mode of the amino acid and Ir in order to enhance the chiral control ability of the amino acid to the Ir(III) catalyst. The chiral Ir(III) catalyst is designed and synthesized for the first time, and the selectivity reaches up to 99% ee when the catalyst is successfully applied to the high-efficiency asymmetric synthesis of chiral gamma-cyclolactam, so the catalyst has superior stereo control ability.
Oxidative Damage in Aliphatic Amino Acids and Di- and Tripeptides by the Environmental Free Radical Oxidant NO3?: the Role of the Amide Bond Revealed by Kinetic and Computational Studies
Nathanael, Joses G.,Wille, Uta
, p. 3405 - 3418 (2019/03/11)
Kinetic and computational data reveal a complex behavior of the important environmental free radical oxidant NO3? in its reactions with aliphatic amino acids and di- and tripeptides, suggesting that attack at the amide N-H bond in the peptide backbone is a highly viable pathway, which proceeds through a proton-coupled electron transfer (PCET) mechanism with a rate coefficient of about 1 × 106 M-1 s-1 in acetonitrile. Similar rate coefficients were determined for hydrogen abstraction from the α-carbon and from tertiary C-H bonds in the side chain. The obtained rate coefficients for the reaction of NO3? with aliphatic di- and tripeptides suggest that attack occurs at all of these sites in each individual amino acid residue, which makes aliphatic peptide sequences highly vulnerable to NO3?-induced oxidative damage. No evidence for amide neighboring group effects, which have previously been found to facilitate radical-induced side-chain damage in phenylalanine, was found for the reaction of NO3? with side chains in aliphatic peptides.
