32387-83-0Relevant articles and documents
Cytotoxic ring A-modified steroid analogues derived from Grundmann's ketone
Mayer, Christoph D.,Bracher, Franz
, p. 3227 - 3236 (2011)
A series of steroid and azasteroid analogues containing a six-membered ring A with various functionalities were synthesized. Furthermore, the syntheses of tetracyclic analogues bearing a five-membered A-ring and the syntheses of a number of bicyclic secosteroid analogues were carried out. All compounds were tested for their antibacterial, antifungal and cytotoxic activities. Among all tested compounds 7 and 9 showed outstanding cytotoxic activities but were devoid of antimicrobial activities. The cytotoxic activities of compounds 7, 9 and 10 were initially verified by the National Cancer Institute (NCI) in a one-dose 60 cell assay. In accordance with our results 7 and 9 satisfied pre-determined threshold inhibition criteria for progression to the 5-dose NCI screening, which revealed a selective activity profile for both candidates.
Oxidation of bromide by tert-butyl hypochlorite
Pastoriza, Cristina,Antelo, Juan Manuel,Crugeiras, Juan
, p. 629 - 637 (2013)
The kinetics of the oxidation reaction of bromide by tert-butyl hypochlorite (tBuOCl) was studied at 25°C, ionic strength 0.5 M, and under isolation conditions. A stopped-flow spectrophotometer was employed for monitoring the reactions. Kinetic studies show that the reaction is first order with respect to [Br-] and [tBuOCl]. Linear dependences of the proton concentration, in perchloric acid medium, and the buffer solution concentration were found on the rate constant. The activation parameters were calculated using the Arrhenius and Eyring equations from the kinetic studies performed to analyze the influence of temperature on the rate constant. The results are consistent with a reaction mechanism of general acid catalysis. The catalytic constants were obtained for the oxidation of bromide by tert-butyl hypochlorite. The slope obtained for the Broensted relationship was 0.36.
Asymmetric synthesis of new antimalarial aminoquinolines through Sharpless aminohydroxylation
Bentzinger, Guillaume,De Souza, Wesley,Mullié, Catherine,Agnamey, Patrice,Dassonville-Klimpt, Alexandra,Sonnet, Pascal
, p. 1 - 11 (2016)
Recently, the asymmetric synthesis and biological activity of (R)- and (S)-4-aminoquinolinemethanols 1 as mefloquine analogues were reported. Several compounds showed very promising antimalarial activity, in the nanomolar range, against Plasmodium falciparum 3D7 and W2. Enantiomers with an (S)-absolute configuration were more active than their (R)-counterparts by a factor ranging from 2 to 15-fold, according to the compound and the plasmodial strain considered. In continuation of our work, three novel series of enantiopure aminoquinolines 2a, 2b, and 3 were synthesized via an asymmetric aminohydroxylation reaction. These compounds were obtained in 2 or 4 steps from a common amidoalcohol key-intermediate 4. They displayed IC50 values close to the micromolar against the two P. falciparum strains 3D7 and W2. The study of the structure-activity relationships allows us to better understand the importance of the substitution and of the stereochemistry at C11 and C12 position of the quinoline and gives tracks for the design of new compounds more active against the plasmodial strains.
Development of Simplified Heterocyclic Acetogenin Analogues as Potent and Selective Trypanosoma brucei Inhibitors
Florence, Gordon J.,Fraser, Andrew L.,Gould, Eoin R.,King, Elizabeth F.,Menzies, Stefanie K.,Morris, Joanne C.,Thomson, Marie I.,Tulloch, Lindsay B.,Zacharova, Marija K.,Smith, Terry K.
, p. 1503 - 1506 (2016)
Neglected tropical diseases caused by parasitic infections are an ongoing and increasing concern. They are a burden to human and animal health, having the most devastating effect on the world′s poorest countries. Building upon our previously reported triazole analogues, in this study we describe the synthesis and biological testing of other novel heterocyclic acetogenin-inspired derivatives, namely 3,5-isoxazoles, furoxans, and furazans. Several of these compounds maintain low-micromolar levels of inhibition against Trypanosoma brucei, whilst having no observable inhibitory effect on mammalian cells, leading to the possibility of novel lead compounds for selective treatment.
A modular, low footprint and scalable flow platform for the expedient α-aminohydroxylation of enolizable ketones
Kassin, Victor-Emmanuel H.,Morodo, Romain,Toupy, Thomas,Jacquemin, Isaline,Van Hecke, Kristof,Robiette, Rapha?l,Monbaliu, Jean-Christophe M.
supporting information, p. 2336 - 2351 (2021/04/07)
The unique reactivity profile of α-chloronitroso derivatives is expressed to its fullest potential through the development of an integrated, modular and scalable continuous flow process for the electrophilic α-aminohydroxylation of various enolizable ketones. Flow conditions contribute to mitigating the high reactivity and toxicity of α-chloronitroso derivatives and provide an efficient, versatile and safe protocol for the α-aminohydroxylation of ketones with a minimal footprint. Fundamental aspects of the α-aminohydroxylation process were computed by DFT and further supported the experimental observations, hence leading to the unprecedented α-chloronitroso-based α-aminohydroxylation of primary, secondary and tertiary substrates. Recycling of the carbon backbone of the α-chloronitroso derivatives provides a high atom economy for the preparation of value-added molecules. This work showcases α-chloronitroso derivatives as economic and efficient vehicles for transferring electrophilic synthons of hydroxylamine toward nucleophilic enolates. A representative range of precursors and analogs of pharmaceutical active ingredients, including WHO essentials and drugs in shortage (such as epinephrine and ketamine), are prepared within minutes according to a fully concatenated process. The process features sequential modules with distinct unit operations including chemical transformations and multiple in-line extractions. The process relies on an upstream chemical Generator that manages the preparation of α-chloronitroso derivatives and that feeds downstream a series of α-aminohydroxylation modules. The setup is amenable to the addition of libraries of compounds for feeding upstream the process of discovery in medicinal chemistry and is transposable to pilot scale. Several layers of in-line analytical procedures are featured to improve process control and safety.
Tetrasubstituted 1,3-Enynes by Gold-Catalyzed Direct C(sp2)-H Alkynylation of Acceptor-Substituted Enamines
Han, Chunyu,Tian, Xianhai,Zhang, Huili,Rominger, Frank,Hashmi, A. Stephen K.
supporting information, p. 4764 - 4768 (2021/06/30)
A gold-catalyzed synthesis of tetrasubstituted 1,3-enynes from hypervalent iodine(III) reagents and activated alkenes is reported. This reaction involves an in situ formed alkynyl Au(III) species and a subsequent direct C(sp2)-H functionalization of alkenes, offering 26 enynes in 62-92% yield with excellent functional group tolerance.
Dual Gold/Silver Catalysis: Indolizines from 2-Substituted Pyridine Derivatives via a Tandem C(sp3)–H Alkynylation/Iminoauration
Han, Chunyu,Liu, Yaowen,Tian, Xianhai,Rominger, Frank,Hashmi, A. Stephen K.
supporting information, p. 9480 - 9484 (2021/12/17)
A dual gold/silver-catalyzed cascade C(sp3)–H alkynylation/iminoauration of 2-substituted pyridines with hypervalent iodine(III) reagents for the synthesis of indolizines is described. This novel reaction involves the formation of an alkynyl Au(III) species, a dual gold/silver-catalyzed C(sp3)–H functionalization, and a subsequent iminoauration process. A number of indolizines bearing diverse functionalities were prepared in good to excellent yield. Furthermore, a gram-scale reaction was efficiently conducted.
Twofold Radical-Based Synthesis of N, C-Difunctionalized Bicyclo[1.1.1]pentanes
Anderson, Edward A.,Mousseau, James. J.,Nugent, Jeremy,Owen, Benjamin,Pickford, Helena D.,Smith, Russell C.
supporting information, p. 9729 - 9736 (2021/07/19)
Bicyclo[1.1.1]pentylamines (BCPAs) are of growing importance to the pharmaceutical industry as sp3-rich bioisosteres of anilines and N-tert-butyl groups. Here we report a facile synthesis of 1,3-disubstituted BCPAs using a twofold radical functionalization strategy. Sulfonamidyl radicals, generated through fragmentation of α-iodoaziridines, undergo initial addition to [1.1.1]propellane to afford iodo-BCPAs; the newly formed C-I bond in these products is then functionalized via a silyl-mediated Giese reaction. This chemistry also translates smoothly to 1,3-disubstituted iodo-BCPs. A wide variety of radical acceptors and iodo-BCPAs are accommodated, providing straightforward access to an array of valuable aniline-like isosteres.
Silicon-Free SuFEx Reactions of Sulfonimidoyl Fluorides: Scope, Enantioselectivity, and Mechanism
Baggerman, Jacob,Jordaan, Daan,Liang, Dong-Dong,Streefkerk, Dieuwertje E.,Wagemakers, Jorden,Zuilhof, Han
supporting information, p. 7494 - 7500 (2020/03/23)
SuFEx reactions, in which an S?F moiety reacts with a silyl-protected phenol, have been developed as powerful click reactions. In the current paper we open up the potential of SuFEx reactions as enantioselective reactions, analyze the role of Si and outline the mechanism of this reaction. As a result, fast, high-yielding, “Si-free” and enantiospecific SuFEx reactions of sulfonimidoyl fluorides have been developed, and their mechanism shown, by both experimental and theoretical methods, to yield chiral products.
Merging Natural Products: Muraymycin–Sansanmycin Hybrid Structures as Novel Scaffolds for Potential Antibacterial Agents
Niro, Giuliana,Weck, Stefanie C.,Ducho, Christian
, p. 16875 - 16887 (2020/11/30)
To overcome bacterial resistances, the need for novel antimicrobial agents is urgent. The class of so-called nucleoside antibiotics furnishes promising candidates for the development of new antibiotics, as these compounds block a clinically unexploited bacterial target: the integral membrane protein MraY, a key enzyme in cell wall (peptidoglycan) biosynthesis. Nucleoside antibiotics exhibit remarkable structural diversity besides their uridine-derived core motifs. Some sub-classes also show specific selectivities towards different Gram-positive and Gram-negative bacteria, which are poorly understood so far. Herein, the synthesis of a novel hybrid structure is reported, derived from the 5′-defunctionalized uridine core moiety of muraymycins and the peptide chain of sansanmycin B, as a new scaffold for the development of antimicrobial agents. The reported muraymycin–sansanmycin hybrid scaffold showed nanomolar activity against the bacterial target enzyme MraY, but displayed no significant antibacterial activity against S. aureus, E. coli, and P. aeruginosa.
