40641-03-0Relevant articles and documents
Fluorescence Decay of Tryptophan Conformers in Aqueous Solution
Szabo, A. G.,Rayner, D. M.
, p. 554 - 563 (1980)
The fluorescence decay parameters of aqueous solutions of tryptophan and several tryptophan and indole derivatives are reported.The fluorescence decays of tryptophan, tryptophan ethyl ester, and 5-methyl- and 6-methyltryptophan are all described by double exponential kinetics.The relative proportions of the two components vary with emission wavelength.The fluorescence of all other derivatives obeys single exponential decay kinetics.In the case of tryptophan the two components, τ1 = 3.1 ns and τ2 = 0.51 ns, had fluorescence maxima at 350 and 335 nm, respectively.The origin of this behavior is discussed in terms of several models bur is most consistent with the assignment of the emission to different rotamers or conformers of the alanyl side chain of tryptophan.
Anhydrous Hydrogen Iodide-Mediated Reductive Indolization of in Situ-Generated Cyclopropyl Hydrazones
Yasui, Motohiro,Fujioka, Hiroki,Takeda, Norihiko,Ueda, Masafumi
supporting information, p. 43 - 47 (2021/12/17)
Fischer-type indolization of N-aryl-C-cyclopropyl hydrazones generated in situ followed by chemoselective reduction using tert-butyl iodide as an anhydrous HI generator was developed. This protocol provides indoles bearing carboxylic acid derivative units. A series of control experiments indicated the HI-mediated formation and reduction of spirocyclopropyl indolenines. Anhydrous HI functions as a Br?nsted acid as well as a reducing agent, facilitating the successful conversion of unstable reaction intermediates and iodinated mixtures in equilibrium.
4-Alkyl-1,2,4-triazole-3-thione analogues as metallo-β-lactamase inhibitors
Gavara, Laurent,Legru, Alice,Verdirosa, Federica,Sevaille, Laurent,Nauton, Lionel,Corsica, Giuseppina,Mercuri, Paola Sandra,Sannio, Filomena,Feller, Georges,Coulon, Rémi,De Luca, Filomena,Cerboni, Giulia,Tanfoni, Silvia,Chelini, Giulia,Galleni, Moreno,Docquier, Jean-Denis,Hernandez, Jean-Fran?ois
supporting information, (2021/06/15)
In Gram-negative bacteria, the major mechanism of resistance to β-lactam antibiotics is the production of one or several β-lactamases (BLs), including the highly worrying carbapenemases. Whereas inhibitors of these enzymes were recently marketed, they only target serine-carbapenemases (e.g. KPC-type), and no clinically useful inhibitor is available yet to neutralize the class of metallo-β-lactamases (MBLs). We are developing compounds based on the 1,2,4-triazole-3-thione scaffold, which binds to the di-zinc catalytic site of MBLs in an original fashion, and we previously reported its promising potential to yield broad-spectrum inhibitors. However, up to now only moderate antibiotic potentiation could be observed in microbiological assays and further exploration was needed to improve outer membrane penetration. Here, we synthesized and characterized a series of compounds possessing a diversely functionalized alkyl chain at the 4-position of the heterocycle. We found that the presence of a carboxylic group at the extremity of an alkyl chain yielded potent inhibitors of VIM-type enzymes with Ki values in the μM to sub-μM range, and that this alkyl chain had to be longer or equal to a propyl chain. This result confirmed the importance of a carboxylic function on the 4-substituent of 1,2,4-triazole-3-thione heterocycle. As observed in previous series, active compounds also preferentially contained phenyl, 2-hydroxy-5-methoxyphenyl, naphth-2-yl or m-biphenyl at position 5. However, none efficiently inhibited NDM-1 or IMP-1. Microbiological study on VIM-2-producing E. coli strains and on VIM-1/VIM-4-producing multidrug-resistant K. pneumoniae clinical isolates gave promising results, suggesting that the 1,2,4-triazole-3-thione scaffold worth continuing exploration to further improve penetration. Finally, docking experiments were performed to study the binding mode of alkanoic analogues in the active site of VIM-2.
Synthesis of CF3-Containing Spirocyclic Indolines via a Red-Light-Mediated Trifluoromethylation/Dearomatization Cascade
Gianetti, Thomas L.,Mei, Liangyong,Moutet, Jules,Stull, Savannah M.
supporting information, p. 10640 - 10653 (2021/07/31)
A red-light-mediated nPr-DMQA+-catalyzed cascade intramolecular trifluoromethylation and dearomatization of indole derivatives with Umemoto's reagent has been developed. This protocol provides a facile and efficient approach for the construction of functionalized and potentially biologically important CF3-containing 3,3-spirocyclic indolines with moderate to high yields and excellent diastereoselectivities under mild conditions. The success of multiple gram-scale (1 and 10 g) experiments further highlights the robustness and practicality of this protocol and the merit of the employment of red light. Mechanistic studies support the formation of a crucial CF3 radical species and a dearomatized benzyl carbocation intermediate.
SUBSTITUTED TETRAHYDROPYRANOINDOLES, DERIVATIVES THEREOF, AND THEIR METHODS OF SYNTHESIS AND USE
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Paragraph 0160; 0161, (2021/01/25)
Disclosed herein are tetrahydropyranoindole compounds and derivatives thereof, as well as their methods of synthesis and use. The disclosed compounds may be synthesized by methods that utilize a cooperative hydrogen bond donor/Br?nsted acid system. The disclosed compounds may be useful for treating a disease, disorder, or a symptom thereof in a subject in need thereof, such as pain, swelling, and joint stiffness. The disclosed compounds also may be useful for treating cell proliferative diseases and disorders such as cancer.
COMPOUNDS FOR TREATING RAC-GTPASE MEDIATED DISORDER
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Page/Page column 33, (2019/08/08)
This disclosure relates to certain compounds that are effective in the treatment of a Rac-GTPase mediated disorder (e.g., acute lymphoblastic or chronic myelogenous leukemia), as well as methods for the manufacture of and the use of these compounds (e.g.,
Electrochemical Hydrogenation with Gaseous Ammonia
Li, Jin,He, Lingfeng,Liu, Xu,Cheng, Xu,Li, Guigen
supporting information, p. 1759 - 1763 (2019/01/16)
As a carbon-free and sustainable fuel, ammonia serves as high-energy-density hydrogen-storage material. It is important to develop new reactions able to utilize ammonia as a hydrogen source directly. Herein, we report an electrochemical hydrogenation of alkenes, alkynes, and ketones using ammonia as the hydrogen source and carbon electrodes. A variety of heterocycles and functional groups, including for example sulfide, benzyl, benzyl carbamate, and allyl carbamate were well tolerated. Fast stepwise electron transfer and proton transfer processes were proposed to account for the transformation.
A Cooperative Hydrogen Bond Donor–Br?nsted Acid System for the Enantioselective Synthesis of Tetrahydropyrans
Maskeri, Mark A.,O'Connor, Matthew J.,Jaworski, Ashley A.,Davies, Anna V.,Scheidt, Karl A.
supporting information, p. 17225 - 17229 (2018/12/05)
Carbocations stabilized by adjacent oxygen atoms are useful reactive intermediates involved in fundamental chemical transformations. These oxocarbenium ions typically lack sufficient electron density to engage established chiral Br?nsted or Lewis acid catalysts, presenting a major challenge to their widespread application in asymmetric catalysis. Leading methods for selectivity operate primarily through electrostatic pairing between the oxocarbenium ion and a chiral counterion. A general approach to new enantioselective transformations of oxocarbenium ions requires novel strategies that address the weak binding capabilities of these intermediates. We demonstrate herein a novel cooperative catalysis system for selective reactions with oxocarbenium ions. This new strategy has been applied to a highly selective and rapid oxa-Pictet–Spengler reaction and highlights a powerful combination of an achiral hydrogen bond donor with a chiral Br?nsted acid.
Radical-Mediated Dearomatization of Indoles with Sulfinate Reagents for the Synthesis of Fluorinated Spirocyclic Indolines
Ryzhakov, Dmytro,Jarret, Maxime,Guillot, Régis,Kouklovsky, Cyrille,Vincent, Guillaume
supporting information, p. 6336 - 6339 (2017/12/08)
The dearomative introduction of trifluoromethyl and 1,1-difluoroethyl radicals, generated from their corresponding sulfinate salts, into the C2 position of indole derivatives allows the diastereoselective synthesis of three-dimensional 3,3-spirocyclic indolines over C-H functionalized indoles.
Ethyl 2-cyano-2-(2-nitrobenzenesulfonyloxyimino)acetate (o -NosylOXY): A recyclable coupling reagent for racemization-free synthesis of peptide, amide, hydroxamate, and ester
Dev, Dharm,Palakurthy, Nani Babu,Thalluri, Kishore,Chandra, Jyoti,Mandal, Bhubaneswar
, p. 5420 - 5431 (2014/07/08)
Ubiquitousness of amide and ester functionality makes coupling reactions extremely important. Although numerous coupling reagents are available, methods of preparation of the common and efficient reagents are cumbersome. Those reagents generate a substantial amount of chemical waste and lack recyclability. Ethyl 2-cyano-2-(2-nitrobenzenesulfonyloxyimino)acetate (o-NosylOXY), the first member of a new generation of coupling reagents, produces byproducts that can be easily recovered and reused for the synthesis of the same reagent, making the method more environmentally friendly and cost-effective. The synthesis of amides, hydroxamates, peptides, and esters using this reagent is described. The synthesis of the difficult sequences, for example, the islet amyloid polypeptide (22-27) fragment (with a C-terminal Gly, H-Asn-Phe-Gly-Ala-Ile-Leu-Gly-NH 2) and acyl carrier protein (65-74) fragment (H-Val-Gln-Ala-Ala-Ile- Asp-Tyr-Ile-Asn-Gly-OH), following the solid-phase peptide synthesis (SPPS) protocol and Amyloid β (39-42) peptide (Boc-Val-Val-IIe-Ala-OMe), following solution-phase strategy is demonstrated. Remarkable improvement is noticed with respect to reaction time, yield, and retention of stereochemistry. A mechanistic investigation and recyclability are also described.
