查看更多>>摘要：Trifluoroethylthio group (SCH2CF3) is a key functionality in several pharmaceutical and agrochemical compounds, the methods for the installation of the 2,2,2-trifluoroethylthio group are sought after. Herein, we report a copper-catalyzed trifluoroethylthiolation reaction of S-(2,2,2-trifluoroethyl) benzene-sulfonothioates and phenylboronic acids at room temperature. The reaction achieved the insertion of trifluoroethylthio moiety to efficiently obtain various substituted aryl 2,2,2-trifluoroethyl thioethers in good yields. Mechanistic investigation indicates the trifluoroethylthiolation radical is involved in the catalytic circle. Moreover, trifluoroethylthiolated clofibrate was synthesized in a particular fashion. (C) 2021 Published by Elsevier Ltd.
查看更多>>摘要：A formal two-carbon insertion into b-ketoesters with vinylmetal has been developed for the rapid syn-thesis of d-ketoesters. This method features high efficiency, simple operation, and mild conditions with-out the usage of bases and catalysts. The reaction is postulated to proceed via a tandem process involving nucleophilic addition of vinylmetal to ketone, retro-aldol reaction to give an enolate anion and an enone, and finally Michael addition of these two intermediates. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Herein, we report the design, synthesis and application of a borylated amidoxime reagent for the direct synthesis of functionalized oxadiazole and quinazolinone derivatives. This reagent exhibits broad synthetic utility to obtain a variety of biologically relevant drug-like molecules. It can be easily prepared at large scale from relatively inexpensive reagents, and can undergo facile transformations to obtain target compounds. The developed amidoxime reagent was synthesized from 4-(4,4,5,5-tetramethyl-1,3,2dioxaborolan-2-yl)benzonitrile and hydroxyl amine hydrochloride using N,N-diisopropylethylamine as a base in ethanol under reflux conditions. Overall advantages include a metal-free route to boronated oxadiazoles, quinazolinone derivatives, and restriction of the multistep sequences. Importantly, the boron-rich pharmacophore derived compounds were obtained through an efficient and inexpensive strategy. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A number of bioorthogonal reactions have been designed for the preparation of functional biomolecules to study their biological processes. Among them, the reaction induced by X-irradiation has attracted specific attention because it offers high biopermeability and ease of control of the reaction spatiotemporally. Herein, we demonstrate a Copper-catalysed azide-alkyne cycloaddition initiated by hypoxic X-irradiation. In the system, monovalent copper ions (Cu(I)) were generated by the radiolytic reduction of Cu (II), and the resulting metal ion accelerated the coupling between azide and acetylene molecules. We also found that the present reaction could be applied to the modification of oligodeoxynucleotides bearing acetylene unit even in shielded reaction environments by pork meat. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Trifluoromethyl moiety in bioactive compounds can dramatically change both the physicochemical and physiological properties, which could further improve both the pharmacokinetic and pharmacological profiles. It has therefore become indispensable to develop an efficient and mild synthetic methodology for the incorporation of trifluoromethyl group. In present study, a green, mild and practical method which allows for the transition-metal-free, direct C-H radical trifluoromethylation of nitroimidazoles with Togni's regent II as the CF3 radical precursor is described. Diverse nitroimidazoles and their drug molecules were smoothly transformed into trifluoromethylated compounds in moderate to good yields under mild conditions. This new method provides an alternative approach for the prepare of trifluoromethylated compounds, as well as late-stage modification of bioactive nitroimidazoles. (C) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Cobalt-catalyzed cross-couplings of nitrogen-containing heterocyclic phosphonium salts with arylmagnesium halides proceeded efficiently with the aid of cobalt(II) catalyst and copper(I) salt in tetrahydrofuran at ambient temperature, producing the desired 4-arylated pyridine, quinoline, and quinoxaline in modest to good yields. CO 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Synthetic manipulation of the torsion angles in non-planar pi-conjugated dibenzo[g,p]chrysene (DBC) core was described. We prepared DBC scaffolds having four bromines at two bays, and found lithium -bromine exchange procedures enabled to create new DBC derivatives. Crystallographic analyses revealed the largest torsion angle of 57.4 degrees in a tetra-sulfonyl-substituted DBC and the smallest torsion angle 31.8 degrees in a bis-silicon-bridged DBC. With the aid of computational method, these results mean the skeletal fused ring is flexibly movable within a range of 25.6 degrees. This study provides us an intellectual basis for development of distortion-featured functional organic materials. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A one-pot approach which provides a series of cyclobutenecarboxylates in moderate to excellent yields has been developed. This strategy involves visible light-induced [2+2]-photocycloaddition of quinolinones with 1-bromo-1-trifluoromethylethene, followed by tandem sodium alkoxide-promoted elimination, nucleophilic vinylic substitution and hydrolysis. The in-situ generated gem-difluoroalkene is the key intermediate to achieve this transformation. Excellent functional group compatibility and high regioselectivity render the method flexibility and practicability. It is worthy to note that cyclobutenecarboxylic acid can be easily obtained in this protocol, further demonstrating the synthetic potential of this strategy. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：We report the first total synthesis of the macrocyclic decapeptide stylopeptide II (1), which was isolated from the Papua New Guinea marine sponge of the Hymeniacidon genus (formerly Stylotella sp). The methodology to synthesize this compound exploitsthe oxime resin as solid support and is highly efficient allowing the preparation of the macrocyclic decapeptide without a chromatographic purification step. Notably, stylopeptide II (1) was rapidly prepared at gram-scale without any detectable amounts of undesired side products that could have arisen from the coupling, deprotection, cyclization, epimerization and dimerization reactions. The methology is general and accelerates the large-scale synthesis of macrocyclic peptides. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：We report here the 2'-azidomethyl modified uridine nucleoside (2'-AmU) can be efficiently synthesized and employed in the labeling study of nascent deoxynucleic acid of interest using fluorophore with alkyne (DBCO-Cy5). This new DNA labeling tool using uridine variant (2'-AmU) displays intensive application potential considering the several advantages it possesses, including readily available, rather small size (minimal perturbation), reversible regulation and easy subjected to click reaction. (C) 2022 Elsevier Ltd. All rights reserved.
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