We have explored the net-[4 + 2]-cycloadditions of a variety of aryl (or alkenyl) alkynes. Tautomerization via base-catalyzed alkyne-to-allene isomerization produces a transient allene, which undergoes stepwise cyclization with not only a pendant alkyne but also a nitrile. The operative mechanisms for these reactions were studied by density functional theory and compared with the slower thermal cyclization of the precursor alkyne.
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http://dx.doi.org/10.1021/acs.orglett.2c00491 | DOI Listing |
Chem Commun (Camb)
December 2024
Department of Chemistry and Centre for Green Chemistry and Catalysis, Université de Montréal, 1375 Avenue Thérèse-Lavoie-Roux, Montréal, QC, H2V 0B3, Canada.
A terphenyl diyne (TPDY) macrocycle, 3,5-TPDY, has been developed incorporating a bent 1,3-diyne that is active in SPAAC processes affording atropoisomeric triazole products, as well as cycloadditions with diazoacetates and tetrazines. A pendant amine allowed bioconjugation of TPDY to two proteins in a microbial transglutaminase-catalyzed reaction. In contrast to many cycloalkyne SPAAC reagents, the TPDY stabilization occurs interactions of π and π* orbitals of the adjacent alkynes.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States.
The selective removal of solutes is crucial for ensuring a sustainable water supply, recovering resources, and cost-effective biomanufacturing. Adsorptive membranes are promising in this regard due to their rapid mass transfer and low energy demands. However, state-of-the-art adsorptive membranes offer limited pore sizes and surface chemistries.
View Article and Find Full Text PDFChemistry
November 2024
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
By virtue of the high reliability of click chemistry, polymers with clickable groups provide a useful platform for the rapid synthesis of polymer materials with diverse functionalities and architectures. However, the polymerization of clickable vinyl monomers with a concurrent regulation on tacticity remains underdeveloped. Herein, we report the successful development of a stereoselective cationic copolymerization of C-C triple bond-containing vinyl ethers with simple alkyl vinyl ethers by employing confined Brønsted acid as catalyst, which allows for the synthesis of alkyne-functionalized vinyl ether copolymers with high isotacticity (up to 90 % m), controlled molecular weight, and variable content of C-C triple bonds.
View Article and Find Full Text PDFJ Org Chem
April 2024
School of Chemistry, University of Hyderabad, Hyderabad 500 046, Telangana, India.
[Au]-catalyzed and substrate-dependent intramolecular cyclization of sulfonyl ene-amides with a pendant propargyl group afford tetrasubstituted pyrroles, -aminophenols, or 1,6-dihydropyridine carbaldehydes. While the pyrroles and aminophenols are formed when the propargylic alkyne is terminal, dihydropyridines are formed when internal alkyne is present. Internal alkyne substrates with 2-thienyl and 3-thienyl groups give different types of dihydropyridines.
View Article and Find Full Text PDFThe stimulator of interferon genes (STING) pathway links innate and adaptive antitumor immunity and therefore plays an important role in cancer immune surveillance. This has prompted widespread development of STING agonists for cancer immunotherapy, but pharmacological barriers continue to limit the clinical impact of STING agonists and motivate the development of drug delivery systems to improve their efficacy and/or safety. To address this challenge, we developed SAPCon, a STING-activating polymer-drug conjugate platform based on strain-promoted azide-alkyne cycloaddition of dimeric-amidobenzimidazole (diABZI) STING agonists to hydrophilic polymer chains through an enzyme-responsive chemical linker.
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