The scope of the transesterification reaction between beta-fluorinated alpha-imino esters and various electrophiles in the presence of TBAF as fluorine source is described. The reaction is highly selective for alkyl iodides, bromides, and mesylates, while alkyl chlorides react at a significantly slower rate and tosylates do not react under the reaction conditions. This methodology represents a simple and useful alternative for the preparation of a wide variety of fluorinated alpha-imino esters.
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http://dx.doi.org/10.1021/jo800567a | DOI Listing |
J Org Chem
January 2025
Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
Herein, we report a gold(I)-catalyzed cascade cyclization of azido-alkynes bearing an enol ester moiety, leading to indole-fused eight-membered rings. This method allows for the one-step construction of indole and tetrahydroazocin-4-one via an α-imino gold carbene intermediate. The resulting scaffold would be useful for accessing natural products with an eight-membered ring-fused indole moiety.
View Article and Find Full Text PDFJ Org Chem
July 2024
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208 016, India.
An organocatalytic enantio- and diastereoselective synthesis of hexahydropyrrolo[2,3-]indole-containing tetrasubstituted α-amino allenoates, exhibiting both axial and central chirality, has been accomplished via cascade dearomatization-cyclization reaction. The γ-addition to β,γ-alkynyl-α-imino esters provides a library of densely substituted highly enantioenriched allenes in high yields and excellent stereoselectivities. In addition, the scope of this methodology has been extended to tryptophol as well.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
February 2024
Key Laboratory for Advanced Materials, Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
Chromium-catalyzed enantioselective Nozaki-Hiyama-Kishi (NHK) reaction represents one of the most powerful approaches for the formation of chiral carbon-heteroatom bond. However, the construction of sterically encumbered tetrasubstituted stereocenter through NHK reaction still posts a significant challenge. Herein, we disclose a cobalt-catalyzed aza-NHK reaction of ketimine with alkenyl halide to provide a convenient synthetic approach for the manufacture of enantioenriched tetrasubstituted α-vinylic amino acid.
View Article and Find Full Text PDFChem Commun (Camb)
January 2024
College of Chemistry and Materials Science, Key Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, Wuhu, Anhui 241002, P. R. China.
We herein report regio- and enantioselective arylation of β,γ-alkynyl-α-imino esters with pyrroloisoquinolines. Using chiral phosphoric acid catalysts, a wide range of novel axially chiral tetrasubstituted α-amino allenoates were accessed in good yields with excellent enantioselectivities. Notably, this transformation occurred preferentially at the sterically more hindered C1-position of pyrroloisoquinolines.
View Article and Find Full Text PDFMolecules
May 2023
Molecular Chirality Research Center, Graduate School of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba-shi 263-8522, Japan.
1,2,4-Triazole and 1,2,4-triazoline are important components of bioactive molecules and catalysts employed in organic synthesis. Therefore, the efficient synthesis of these components has received significant research attention. However, studies on their structural diversity remain lacking.
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