A copper-catalyzed intramolecular amination occurs at the benzylic C-H of 2-methylbenzamides to deliver the corresponding isoindolinones of great interest in medicinal chemistry. The mild and abundant MnO2 works well as a terminal oxidant, and the reaction proceeds smoothly under potentially explosive organic peroxide-free conditions. Additionally, the directing-group-dependent divergent mechanisms are proposed: 8-aminoquinoline-containing benzamides include a Cu-mediated organometallic pathway whereas an aminyl radical-promoted Hofmann-Loffler-Freytag (HLF)-type mechanism can be operative in the case of N-naphthyl-substituted substrates.
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http://dx.doi.org/10.1021/acs.joc.6b01393 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Nankai University, College of Chemistry, 94 Weijin Rd., 300071, Tianjin, CHINA.
Reliable methods for rapidly constructing C(sp3)-rich three-dimensional polycycles are in high demand for organic synthesis and medicinal chemistry. Although there are various mature systems for synthesizing five- or six-membered polycycles, a catalytic platform for accessing diverse cycloheptanoid-containing polycyclic scaffolds is lacking. Herein, we describe a method for copper-catalyzed intramolecular 2-aminoallyl cation-diene (4 + 3) cycloaddition reactions.
View Article and Find Full Text PDFJ Org Chem
January 2025
College of New Materials and Chemical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, China.
A facile copper-catalyzed, base-controlled cyclization reaction has been developed for the synthesis of 9-membered cycloalkyne and 6-membered heterocycle sultams under mild conditions. This protocol utilizes a copper-catalyzed intramolecular A (alkyne-aldehyde-amine) coupling reaction to efficiently synthesize 9-membered cycloalkyne sultams in yields up to 90%. Alternatively, by substituting NaHCO with DBU, the protocol achieves selective deprotection of the -propargyl group, thereby facilitating the formation of 6-membered heterocyclic sultams, also in high yields.
View Article and Find Full Text PDFJ Am Chem Soc
November 2024
Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
Information can be encoded and stored in sequences of monomer units organized in linear synthetic polymers. Replication of sequence information is of fundamental importance in biology; however, it represents a challenge for synthetic polymer chemistry. A combination of covalent and noncovalent base pairs has been used to achieve high-fidelity templated synthesis of synthetic polymers that encode information as a sequence of different side-chain recognition units.
View Article and Find Full Text PDFJ Org Chem
November 2024
Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Andrés M. del Río (IQAR), Facultad de Farmacia, Universidad de Alcalá, Alcalá de Henares, 28805 Madrid, Spain.
A copper-catalyzed intramolecular synthesis of 3-alkenyl-2-indazoles from 2-alkynylazobenzenes is described. The reaction proceeds in a single step via C-N bond formation and a subsequent 1,2-hydride shift, affording products in high yields. DFT calculations suggest the 1,2-hydride shift as the rate-determining step.
View Article and Find Full Text PDFChem Rec
November 2024
College of Advanced Interdisciplinary Science and Technology (CAIST), Henan University of Technology, Zhengzhou, 450001, China.
Spirooxindoles represent a special scaffold for pharmaceuticals and natural products, and significant advancements have been achieved in their synthesis in recent years. Among these, transition metal catalysis, particularly copper catalysis, has emerged as an efficient and reliable method for the synthesis of spirooxindoles. Based on different reaction types, two distinct substrate types have been summarized and classified by us for constructing spirooxindole scaffolds via intramolecular and intermolecular annulations.
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