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The thianthrene S-oxide (TTSO)-mediated site-selective silylation of arenes has been realized via a thianthrenation/Pd-catalyzed silylation sequence. This method features a broad substrate scope and wide functional group tolerance under mild conditions and allows the synthesis of a set of (hetero)arylsilanes with operationally simple manipulations. The application and generality of the approach were further demonstrated by the late-stage functionalization of marketed drugs. This reaction also represents the first example of a Pd-catalyzed silylation reaction of aryl sulfonium salts.Quinolone-containing natural products are widely found in bacteria, fungi, and plants. The fungal quinolactacins, which are N-methyl-4-quinolones, display a wide spectrum of biological activities. Here we uncovered a concise nonribosomal peptide synthetase pathway involved in quinolactacin A biosynthesis from Penicillium by using heterologous reconstitution and in vitro enzymatic synthesis. The N-desmethyl analog of quinolactacin A was accessed through the construction of a hybrid bacterial and fungi pathway in the heterologous host.A diverse chemoselective insertion reaction of sulfoxonium ylides and thiosulfonates under transition-metal-free conditions is developed, which successfully affords 1,4-diketone compounds, arylthiosulfoxide-ylides, and β-keto thiosulfones, respectively. The nucleophilic addition of two molecular sulfoxonium ylides to construct sulfone-substituted 1,4-dione compounds is the highlight of this work.The construction of complex aza-cycles is of interest to drug discovery due to the prevalence of nitrogen-containing heterocycles in pharmaceutical agents. #link# Herein we report an intramolecular C-H amination approach to afford value-added and complexity-enriched bridged bicyclic amines. Guided by density functional theory and nuclear magnetic resonance investigations, we determined the unique roles of light and heat activation in the bicyclization mechanism. We applied both light and heat activation in a synergistic fashion, achieving gram-scale bridged aza-cycle synthesis.A gold(I)-catalyzed cascade transformation of N-alkynic 2-ynamides for the rapid and efficient synthesis of the indolizidine scaffold is developed. Through a sequential nucleophilic cyclization/enyne cycloisomerization/1,2-migration process, diverse pyrrolo[1,2-b]isoquinolines are obtained under mild conditions in a regiospecific and convergent manner. Various alkyl and aryl migrating groups are tolerated in this process. The electronic effect of the migrating group is comprehensively investigated. The study of the mechanism indicates that the pathway involving a gold carbenoid species is the main pathway and that the 1,2-migration of alkyl and aryl groups to the gold carbenoid occurs in an intramolecular fashion. This cascade reaction is also employed as the key step for the synthesis of a decumbenine B analogue.Efficient access to chiral cyclopentadienyl esters from readily accessible chiral enynyl ester substrates is developed. Typically high levels of chirality transfer realized in this homogeneous gold catalysis are attributed to the intermediacy of a chiral bent allene gold complex. Cyclopentadienyl esters can be prepared in good yields and with excellent enantiomeric excesses. The synthetic utilities of the chiral cyclopentadienyl esters are demonstrated by the Diels-Alder reactions, fluorination, alkylation, and epoxidation without any notable erosion of enantiopurity.Herein, we report a catalyst system for Pd-catalyzed decarbonylative Suzuki-Miyaura cross-coupling of aroyl chlorides with boronic acids to furnish biaryls. This strategy is suitable for a broad range of common aroyl chlorides and boronic acids. The synthetic utility is highlighted in the direct late-stage functionalization of pharmaceuticals and natural products capitalizing on the presence of carboxylic acid moiety. Extensive mechanistic and DFT studies provide key insight into the reaction mechanism and high decarbonylative cross-coupling selectivity.The kalimantacins make up a family of hybrid polyketide-nonribosomal peptide-derived natural products that display potent and selective antibiotic activity against multidrug resistant strains of Staphylococcus aureus. Herein, we report the first total synthesis of kalimantacin A, in which three fragments are prepared and then united via Sonogashira and amide couplings. The enantioselective synthetic approach is convergent, unlocking routes to further kalimantacins and analogues for structure-activity relationship studies and clinical evaluation.An efficient transformation of dibenzoxaborins to dibenzofurans by deborylative ring contraction was achieved under mild conditions using a copper catalyst. The method showed a broad substrate scope enabling the preparation of various dibenzofurans, including those bearing a functional group. The ready availability of various dibenzoxaborins enhances the utility of this method, as demonstrated by the regiodivergent synthesis of dibenzofurans.A novel ynamide-mediated synthesis of thionoesters and dithioesters is described. The selective addition reactions of various monothiocarboxylic acids with ynamide furnish α-thioacyloxyenamides, which undergo transesterification with nucleophilic -OH or -SH species to afford thionoesters and dithioesters, respectively. The broad substrate scope, mild reaction conditions, and excellent yields make this method an attractive synthetic approach to thionoesters and dithioesters.Herein, we describe a Cu-catalyzed approach to directly accessing aromatic heterocyclic amines from cyclic amides. The most-reported methods for cyclic amide conversions to aromatic heterocyclic amines use an activating group, such as a halogen atom or a trifluoromethane sulfonyl group. However, subsequent elimination of activating groups during the amination process results in significant waste. This copper-catalyzed direct amination of cyclic amides in DMF forms aromatic heterocyclic amines with environmental friendliness and readily available reagents. Selleck AR-42 has been proposed for the reaction. Meanwhile, the coordinating effect of the N1 atom is key to the success of this reaction, which provides assistance to the copper ions for the activation and amination of C-O bonds.
Read More: https://www.selleckchem.com/products/AR-42-HDAC-42.html
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