The stereoselective, expedient assembly of the key functionalized isotwistane (bridged tricyclo[4.3.1.0(3,7)]decane) system, 5/6/6 ring, with contiguous quaternary stereocenters in Lycopodium alkaloid palhinine A and its analogues via an intramolecular Diels-Alder strategy is described.
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http://dx.doi.org/10.1021/ol301534r | DOI Listing |
Chem Sci
January 2025
Hubei Research Center of Fundamental Science-Chemistry, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University Wuhan Hubei 430072 China
Developing methodologies for the expedient construction of biologically important δ-valerolactones bearing a privileged azaarene moiety and a sterically congested all-carbon quaternary stereocenter is important and full of challenges. We present herein a novel multicatalytic strategy for the stereodivergent synthesis of highly functionalized chiral δ-valerolactones bearing 1,4-nonadjacent quaternary/tertiary stereocenters by orthogonally merging borrowing hydrogen and Michael addition between α-azaaryl acetates and allylic alcohols followed by lactonization in a one-pot manner. Enabled by Cu/Ru relay catalysis, this cascade protocol offers the advantages of atom/step economy, redox-neutrality, mild reaction conditions, and broad substrate tolerance.
View Article and Find Full Text PDFJ Org Chem
December 2024
Department of Chemistry, Rutgers University, 73 Warren Street, Newark, New Jersey 07102, United States.
A novel iridium-catalyzed [3 + 2] annulation of naphthylamines and α-diazocarbonyl compounds was developed for the rapid assembly of densely functionalized indoles. This new catalytic process represents the first example of a cascade intramolecular nucleophilic cyclization by the N-H insertion of amines. Various naphthylamines and α-diazocarbonyl compounds could be obtained in high yields with excellent functional group tolerance.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2025
Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, China.
The core-shell structure often exhibits unique properties, resulting in superior physical and chemical performance distinct from individual component in the field of photocatalysis. However, traditional prepared methods such as template synthesis and layer-by-layer self-assembly are relatively complex. Therefore, it is necessary to explore an efficient and expedient approach.
View Article and Find Full Text PDFBMJ Mil Health
November 2024
Department of Orthopaedic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Introduction: Morbidity and mortality from pelvic ring injuries can be mitigated by early and effective external pelvic stabilisation. The field-expedient pelvic splint (FEPS) is a recently described technique to improvise an effective pelvic binder for an austere environment. This technique has not been biomechanically validated.
View Article and Find Full Text PDFChem Sci
July 2024
Laboratory of Asymmetric Catalysis and Synthesis, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
The unique electronic and steric parameters of chiral cyclic alkyl amino carbene (CAAC) ligands render them appealing steering ligands for enantioselective transition-metal catalyzed transformations. Due to the lack of efficient synthetic strategies to access particularly attractive α-chiral CAACs assessment and exploitation of their full synthetic potential remain difficult. Herein, we report a streamlined strategy to assemble a library of diastereo- and enantiomerically pure CAAC ligands featuring the notoriously difficult to access α-quaternary stereogenic centers.
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