6 research outputs found

    Gold-Catalyzed Cyclization of 3‑(2′-Azidoaryl)-1-arylpropargyl Carbonates or 3‑Aryl-1-(2′-azidoaryl)propargyl Carbonates to Produce Quinolines

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    A gold-catalyzed cyclization of 3-(2′-azidoaryl)-1-arylpropargyl carbonates to generate substituted quinolines via a sequence of 3,3-rearrangement, 6-<i>endo</i>-trig cyclization and denitrogenation has been developed. Similar products could be obtained from 3-aryl-1-(2′-azidoaryl)­propargyl carbonates under different gold catalytic conditions via a sequential 6-<i>endo</i>-dig cyclization, denitrogenation, and 1,2-H shift process

    Gold-Catalyzed Cyclization of 3‑(2′-Azidoaryl)-1-arylpropargyl Carbonates or 3‑Aryl-1-(2′-azidoaryl)propargyl Carbonates to Produce Quinolines

    No full text
    A gold-catalyzed cyclization of 3-(2′-azidoaryl)-1-arylpropargyl carbonates to generate substituted quinolines via a sequence of 3,3-rearrangement, 6-<i>endo</i>-trig cyclization and denitrogenation has been developed. Similar products could be obtained from 3-aryl-1-(2′-azidoaryl)­propargyl carbonates under different gold catalytic conditions via a sequential 6-<i>endo</i>-dig cyclization, denitrogenation, and 1,2-H shift process

    Gold-Catalyzed Cyclization of 3‑(2′-Azidoaryl)-1-arylpropargyl Carbonates or 3‑Aryl-1-(2′-azidoaryl)propargyl Carbonates to Produce Quinolines

    No full text
    A gold-catalyzed cyclization of 3-(2′-azidoaryl)-1-arylpropargyl carbonates to generate substituted quinolines via a sequence of 3,3-rearrangement, 6-<i>endo</i>-trig cyclization and denitrogenation has been developed. Similar products could be obtained from 3-aryl-1-(2′-azidoaryl)­propargyl carbonates under different gold catalytic conditions via a sequential 6-<i>endo</i>-dig cyclization, denitrogenation, and 1,2-H shift process

    Asymmetric Total Syntheses of Aspidodasycarpine, Lonicerine, and the Proposed Structure of Lanciferine

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    Aspidodasycarpine and lonicerine are a pair of epimeric aspidophylline-type alkaloids bearing vicinal quaternary C7 and C16. The first and enantioselective total syntheses of these molecules are described here. A Ru-catalyzed asymmetric transfer hydrogenation established the first stereocenter. An Au-promoted Toste cyclization was exploited to assemble the bridged tetracyclic core and define the geometry of the exocyclic olefin; electron deficient (<i>p</i>-CF<sub>3</sub>C<sub>6</sub>H<sub>4</sub>)<sub>3</sub>P was a suitable ligand for this transformation. An aldol condensation followed by an intramolecular indole C3 alkylation constructed the adjacent quaternary C7 and C16 diastereoselectively, leading to a pentacyclic lactol as an advanced common intermediate for synthesizing both alkaloids. The proposed structure of lanciferine, a highly oxidized congener of aspidodasycarpine, was synthesized from the lactol by tuning the oxidation states of various carbons

    Total Synthesis of Trioxacarcins DC-45-A1, A, D, C, and C7″-<i>epi</i>-C and Full Structural Assignment of Trioxacarcin C

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    Trioxacarcins DC-45-A2, DC-45-A1, A, D, C7″-<i>epi</i>-C, and C have been synthesized through stereoselective strategies involving BF<sub>3</sub>·Et<sub>2</sub>O-catalyzed ketone–epoxide opening and gold-catalyzed glycosylation reactions, and the full structural assignment of trioxacacin C was deciphered via the syntheses of both of its C7″ epimers. The gathered knowledge sets the foundation for the design, synthesis, and biological evalution of analogues of these natural products as potential payloads for antibody–drug conjugates and other delivery systems for targeted and personalized cancer chemotherapy

    Streamlined Total Synthesis of Trioxa­carcins and Its Application to the Design, Synthesis, and Biological Evaluation of Analogues Thereof. Discovery of Simpler Designed and Potent Trioxa­carcin Analogues

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    A streamlined total synthesis of the naturally occurring antitumor agents trioxa­carcins is described, along with its application to the construction of a series of designed analogues of these complex natural products. Biological evaluation of the synthesized compounds revealed a number of highly potent, and yet structurally simpler, compounds that are effective against certain cancer cell lines, including a drug-resistant line. A novel one-step synthesis of anthra­quinones and chloro anthra­quinones from simple ketone precursors and phenyl­selenyl chloride is also described. The reported work, featuring novel chemistry and cascade reactions, has potential applications in cancer therapy, including targeted approaches as in antibody–drug conjugates
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