Light as a reagent: A highly functionalized structure that serves as a daphnane template can be formed by the photorearrangement of a 2,5-cyclohexadienone subunit within a complex tricyclic ring system. The chemistry we describe should not only find use in the total synthesis of resiniferatoxin and related daphnanes, but should also provide useful templates for access to complex analogues.
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http://dx.doi.org/10.1002/1521-3773(20010716)40:14<2694::AID-ANIE2694>3.0.CO;2-D | DOI Listing |
Org Lett
December 2024
Yunnan Key Laboratory of Modern Separation Analysis and Substance Transformation, College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650500, China.
A copper-catalyzed [2,3]-sigmatropic rearrangement of azide-ynamides via selenium ylides is disclosed, which leads to the practical and divergent synthesis of a variety of tricyclic heterocycles bearing a quaternary carbon stereocenter in generally moderate to excellent yields. Significantly, this method represents the first [2,3]-sigmatropic rearrangement of the selenium ylide based on alkynes and an unprecedented [2,3]-sigmatropic rearrangement via α-imino copper carbenes.
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December 2024
School of Pharmaceutical Sciences and Chongqing Key Laboratory of Natural Drug Research, Chongqing University, Chongqing 401331, People's Republic of China.
The asymmetric [5 + 2] cycloaddition of VECs remains to be comparatively rare. Herein, we reported an enantioselective formal [5 + 2] annulation of 3-hydroxyquinolinones and vinylethylene carbonates (VECs) through Pd- and Cu-catalyzed tandem allylation/asymmetric [1,3]-rearrangement/hemiketalization sequences. The strategy exhibits good substrate tolerance, affording a wide range of tricyclic quinolinones bearing two adjacent quaternary stereocenters in moderate to good yields with excellent enantioselectivities.
View Article and Find Full Text PDFOrg Lett
November 2024
School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China.
This study synthesized nitrogen-rich [5,6,5] fused compounds through a novel rearrangement reaction. Owing to its unique zwitterionic salt structure, rearrangement product - exhibits high thermal stability ( > 250 °C), low sensitivity (IS > 40 J, FS > 360 N), and acceptable detonation velocities and pressures (ν = 8520 m s and = 32.53 GPa, respectively), which are better than those of TNT and TATB.
View Article and Find Full Text PDFJ Org Chem
November 2024
Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany.
Nitrogen-containing heterocycles are present in most approved drugs, reflecting the significance of their synthetic strategies. By utilizing oxadiazolone as a nitrenoid (nitrene-like) precursor, we have developed a general strategy for the annulation with nucleophilic heterocycles to access various polycyclic aminoheterocycles. We have discovered that 2-pyrryl-substituted substrates undergo a rearrangement, which indicates a spirocyclization-migration pathway.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2024
School of Pharmaceutical Sciences, Beijing Advanced Innovation Center for Structural Biology, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Tsinghua University, 100084, Beijing, China.
An unprecedented dyotropic rearrangement of β-lactams has been developed, which provides an enabling tool for the synthesis of structurally diverse γ-butyrolactams. Unlike the well-established dyotropic rearrangements of β-lactones, the present reaction probably proceeds through a dual-activation mode, and thus displays unusual reactivity and chemoselectivity. The combined computational and experimental results suggest that the dyotropic rearrangement of β-lactams may proceed through different mechanisms depending on the nature of migrating groups (H, alkyl, or aryl).
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