19901-50-9Relevant academic research and scientific papers
The Role of the Amino Protecting Group during Parahydrogenation of Protected Dehydroamino Acids
Cerutti, Erika,Viale, Alessandra,Nervi, Carlo,Gobetto, Roberto,Aime, Silvio
, p. 11271 - 11279 (2015)
A series of dehydroamino acids endowed with different protective groups at the amino and carboxylate moieties and with different substituents at the double bond have been reacted with parahydrogen. The observed ParaHydrogen Induced Polarization (PHIP) effects in the 1H NMR spectra are strongly dependent on the amino protecting group. DFT calculations allowed us to establish a relationship between the structures of the reaction intermediates (whose energies depend on the amido substitution) and the observed PHIP patterns.
Asymmetric Reduction of Aromatic α-Dehydroamino Acid Esters with Water as Hydrogen Source
Dai, Yuze,Chen, Jingchao,Wang, Zheting,Wang, Ting,Wang, Lin,Yang, Yong,Qiao, Xingfang,Fan, Baomin
supporting information, p. 7141 - 7147 (2021/05/29)
The asymmetric reduction of aromatic α-dehydroamino acid esters with water as the hydrogen source was developed by a Rh/Cu co-catalytic system. The reaction tolerates various functional groups, providing a valuable synthetic tool to access chiral α-amino acid esters readily. Moreover, the present methodology also was applied in the cost-effective and easy to handle preparation of chiral deuterated α-amino esters by using D2O.
Identification and Profiling of a Novel Diazaspiro[3.4]octane Chemical Series Active against Multiple Stages of the Human Malaria Parasite Plasmodium falciparum and Optimization Efforts
Le Manach, Claire,Dam, Jean,Woodland, John G.,Kaur, Gurminder,Khonde, Lutete P.,Brunschwig, Christel,Njoroge, Mathew,Wicht, Kathryn J.,Horatscheck, André,Paquet, Tanya,Boyle, Grant A.,Gibhard, Liezl,Taylor, Dale,Lawrence, Nina,Yeo, Tomas,Mok, Sachel,Eastman, Richard T.,Dorjsuren, Dorjbal,Talley, Daniel C.,Guo, Hui,Simeonov, Anton,Reader, Janette,Van Der Watt, Mari?tte,Erlank, Erica,Venter, Nelius,Zawada, Jacek W.,Aswat, Ayesha,Nardini, Luisa,Coetzer, Theresa L.,Lauterbach, Sonja B.,Bezuidenhout, Belinda C.,Theron, Anjo,Mancama, Dalu,Koekemoer, Lizette L.,Birkholtz, Lyn-Marie,Wittlin, Sergio,Delves, Michael,Ottilie, Sabine,Winzeler, Elizabeth A.,Smith, Dennis,Fidock, David A.,Street, Leslie J.,Basarab, Gregory S.,Duffy, James,Chibale, Kelly
supporting information, p. 2291 - 2309 (2021/03/01)
A novel diazaspiro[3.4]octane series was identified from a Plasmodium falciparum whole-cell high-throughput screening campaign. Hits displayed activity against multiple stages of the parasite lifecycle, which together with a novel sp3-rich scaffold provided an attractive starting point for a hit-to-lead medicinal chemistry optimization and biological profiling program. Structure-activity-relationship studies led to the identification of compounds that showed low nanomolar asexual blood-stage activity (50 nM) together with strong gametocyte sterilizing properties that translated to transmission-blocking activity in the standard membrane feeding assay. Mechanistic studies through resistance selection with one of the analogues followed by whole-genome sequencing implicated the P. falciparum cyclic amine resistance locus in the mode of resistance.
Synthesis and photophysics of benzazole based triazoles with amino acid-derived pendant units. Multiparametric optical sensors for BSA and CT-DNA in solution
Debia, Natalí P.,Rodríguez, Juan J.P.,da Silveira, Carolina H.,Chaves, Otavio A.,Iglesias, Bernardo A.,Rodembusch, Fabiano S.,Lüdtke, Diogo S.
, (2020/04/27)
Herein we report the synthesis of a series of amino acid-derived triazoles by an organocatalytic cycloaddition reaction between azides and carbonyl compounds, catalyzed by a simple amine. These compounds present absorption maxima located in the UV-B ascribed to fully spin and symmetry allowed electronic transitions and a main fluorescence emission in the UV-A (~380 nm) with a relatively large Stokes shift (5700 cm?1). No significant solvatochromism was observed in both ground and excited states. Unexpectedly, the benzoxazole derivatives presented much higher fluorescence quantum yield values (40–80%) of compared to the sulfur analogues (3–6%). In addition, the DNA binding assays indicated that these compounds presented strong interaction with CT-DNA, which could be attributed to π-stacking and intermolecular hydrogen-bonding. The interaction of the benzazoles with bovine serum albumin (BSA) was also investigated, where a suppression mechanism was observed. In each case, docking was performed to better understand the observed interactions.
Aminoalkyl radicals as halogen-atom transfer agents for activation of alkyl and aryl halides
Constantin, Timothée,Juliá, Fabio,Leonori, Daniele,Regni, Alessio,Sheikh, Nadeem S.,Zanini, Margherita
, p. 1021 - 1026 (2020/03/10)
Organic halides are important building blocks in synthesis, but their use in (photo)redox chemistry is limited by their low reduction potentials. Halogen-atom transfer remains the most reliable approach to exploit these substrates in radical processes despite its requirement for hazardous reagents and initiators such as tributyltin hydride. In this study, we demonstrate that a-aminoalkyl radicals, easily accessible from simple amines, promote the homolytic activation of carbon-halogen bonds with a reactivity profile mirroring that of classical tin radicals. This strategy conveniently engages alkyl and aryl halides in a wide range of redox transformations to construct sp3-sp3, sp3-sp2, and sp2-sp2 carbon-carbon bonds under mild conditions with high chemoselectivity.
Synthesis and structure-activity relationship of nitrile-based cruzain inhibitors incorporating a trifluoroethylamine-based P2 amide replacement
Gomes, Juliana C.,Cianni, Lorenzo,Ribeiro, Jean,dos Reis Rocho, Fernanda,da Costa Martins Silva, Samelyn,Batista, Pedro Henrique Jatai,Moraes, Carolina Borsoi,Franco, Caio Haddad,Freitas-Junior, Lucio H.G.,Kenny, Peter W.,Leit?o, Andrei,Burtoloso, Antonio C.B.,de Vita, Daniela,Montanari, Carlos A.
supporting information, (2019/09/30)
The structure-activity relationship for nitrile-based cruzain inhibitors incorporating a P2 amide replacement based on trifluoroethylamine was explored by deconstruction of a published series of inhibitors. It was demonstrated that the P3 biphenyl substituent present in the published inhibitor structures could be truncated to phenyl with only a small loss of affinity. The effects of inverting the configuration of the P2 amide replacement and linking a benzyl substituent at P1 were observed to be strongly nonadditive. We show that plotting affinity against molecular size provides a means to visualize both the molecular size efficiency of structural transformations and the nonadditivity in the structure-activity relationship. We also show how the relationship between affinity and lipophilicity, measured by high-performance liquid chromatography with an immobilized artificial membrane stationary phase, may be used to normalize affinity with respect to lipophilicity.
Asymmetric Synthesis of Functionalized Phenylalanine Derivatives via Rh-Catalyzed Conjugate Addition and Enantioselective Protonation Cascade
Jian, Jia-Hong,Zeng, Hao-Wei,Kuo, Ting-Shen,Wu, Ping-Yu,Wu, Hsyueh-Liang
supporting information, p. 9468 - 9472 (2019/11/28)
The asymmetric conjugate addition of arylboronic acids to N-phthalimidodehydroalanine 1i catalyzed by Rh(I)/L1a enables the facile preparation of chiral functionalized phenylalanines. The reaction proceeds by a conjugate addition and enantioselective protonation cascade, affording a rhodium enolate that undergoes re-face protonation. The reaction tolerates various arylboronic acids and can be used in the gram-scale synthesis of (S)-phenylalanine hydrochloride, demonstrating the reaction scope and the synthetic feasibility of the process.
Cu(OTf)2-Promoted 1,4-addition of alkyl bromides to dehydroalanine
Shin, Jung-Ah,Kim, Jiheon,Lee, Hongsoo,Ha, Sura,Lee, Hee-Yoon
, p. 4558 - 4565 (2019/05/01)
Zn/Cu(OTf)2-mediated addition of alkyl bromides to dehydroalanine (Dha) derivatives including dipeptides and tripeptides in good to high yields under an aqueous medium was developed. This protocol allows selective and biocompatible access to various amino acid units from Dha derivatives.
BABIPhos Family of Biaryl Dihydrobenzooxaphosphole Ligands for Asymmetric Hydrogenation
Li, Guisheng,Zatolochnaya, Olga V.,Wang, Xiao-Jun,Rodríguez, Sonia,Qu, Bo,Desrosiers, Jean-Nicolas,Mangunuru, Hari P. R.,Biswas, Soumik,Rivalti, Daniel,Karyakarte, Shuklendu D.,Sieber, Joshua D.,Grinberg, Nelu,Wu, Ling,Lee, Heewon,Haddad, Nizar,Fandrick, Daniel R.,Yee, Nathan K.,Song, Jinhua J.,Senanayake, Chris H.
supporting information, p. 1725 - 1729 (2018/04/14)
Novel bidentate phosphine ligands BABIPhos featuring a biaryl bis-dihydrobenzooxaphosphole core are presented. Their synthesis was achieved via Pd-catalyzed reductive homocoupling of dihydrobenzooxaphosphole aryl triflates. An efficient route toward various analogues was also established, giving access to phosphines with different electronic and steric properties. The newly obtained ligands demonstrated high efficiency and selectivity in Rh-catalyzed asymmetric hydrogenation of di- and trisubstituted enamides. This new class of ligands is complementary to previously described bidentate benzooxaphosphole ligands BIBOP.
METHOD FOR PRODUCING OPTICALLY ACTIVE CARBOXYLIC ACID ESTER
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Paragraph 0732; 0763; 0764, (2017/01/26)
Provided is a method for producing an optically active carboxylic acid ester at a high yield and with high enantioselectivity using dynamic kinetic resolution, said optically active carboxylic acid ester having an α-nitrogen substituent. This method for producing an optically active carboxylic acid ester includes a step in which racemic carboxylic acid represented by formula (a) and a specific alcohol or phenol derivative are reacted in a polar solvent having a dipole moment of at least 3.5 in the presence of an acid anhydride and an asymmetric catalyst, one enantiomer of the racemic carboxylic acid is selectively esterified, and the other enantiomer is racemized. In formula (a), Ra1 represents a nitrogen-containing heteroaromatic ring group bonded to an assymetric carbon via a nitrogen atom constituting a ring, and Ra2 is an organic group.
