Results 21 to 30 of about 1,577 (174)

Intramolecular Azide to Alkene Cycloadditions for the Construction of Pyrrolobenzodiazepines and Azetidino-Benzodiazepines

Molecules, 2014
The coupling of proline- and azetidinone-substituted alkenes to 2-azidobenzoic and 2-azidobenzenesulfonic acid gives precursors that undergo intramolecular azide to alkene 1,3-dipolar cycloadditions to give imine-, triazoline- or aziridine-containing ...
Karl Hemming, Christopher S. Chambers, Faisal Jamshaid, Paul A. O'Gorman   +3 more
doaj   +1 more source

Organocatalytic Enantioselective Addition of Malonates to Cyclic Imines: A Short Total Synthesis of Tetraponerine T‐1

Angewandte Chemie, EarlyView.
A stereoselective functionalization method of cyclic imines under mild organocatalytic conditions was developed. Bifunctional cinchona alkaloid catalysts combined with carefully optimized reaction conditions to suppress background reactivity enabled highly enantio‐ and diastereoselective addition reactions of malonates to cyclic imines.
Frederic Kölblin, Helma Wennemers
wiley   +2 more sources

1,3-Dipolar Cycloadditions to Bicyclic Olefins. I. 1,3-Dipolar Cycloadditions to Norbornadienes [PDF]

Bulletin of the Chemical Society of Japan, 1977
Abstract The 1,3-dipolar cycloadditions of phenylglyoxylonitrile oxide, benzonitrile-N-phenylimine, or N-phenyl-C-p-nitrophenylnitrone to norbornadiene, 2,3-dicyanonorbornadiene, and 2,3-bis(methoxycarbonyl)norbornadiene give the endo-adducts, together with the exo-adducts.
Hisaji Taniguchi, Toshikazu Ikeda, Yoshihiro Yoshida, Eiji Imoto   +3 more
openaire   +1 more source

Copper nanoparticles on controlled pore glass (CPG) as highly efficient heterogeneous catalysts for “click reactions”

Scientific Reports, 2020
We herein report that supported copper nanoparticles (CuNPs) on commercially available controlled pore glass (CPG), which exhibit high mechanical, thermal and chemical stability as compared to other silica-based materials, serve as a useful heterogeneous
Abdolrahim A. Rafi, Ismail Ibrahem, Armando Córdova   +2 more
doaj   +1 more source

Solvent-Free 1,3-Dipolar Cycloadditions of Nitrones for a More Sustainable Synthesis of Glycomimetics

Reactions
1,3-Dipolar cycloadditions on nitrone dipoles are key reactions to access five-membered heterocycles, which are useful intermediates in the synthesis of biologically relevant glycomimetics.
Debora Pratesi, Alessio Morano, Andrea Goti, Francesca Cardona, Camilla Matassini   +4 more
doaj   +1 more source

A Convenient Synthesis of Novel Isoxazolidine and Isoxazole Isoquinolinones Fused Hybrids

Molecules, 2023
Isoxazolidine, isoxazole, and isoquinolinone rings are present in the structure of several natural products and/or pharmaceutically interesting compounds.
Konstantinos A. Ouzounthanasis, Stergios R. Rizos, Alexandros E. Koumbis   +2 more
doaj   +1 more source

Kinetic Resolution of Alkylidene Norcamphors via a Ligand-Controlled Umpolung-Type 1,3-Dipolar Cycloaddition

iScience, 2019
Summary: Development of a general catalytic and highly efficient method utilizing readily available precursors for the regio- and stereoselective construction of bioactive natural-product-inspired spiro architectures remains a formidable challenge in ...
Chong Shen, Yuhong Yang, Liang Wei, Wu-Wei Dong, Lung Wa Chung, Chun-Jiang Wang   +5 more
doaj   +1 more source

Additive-assisted regioselective 1,3-dipolar cycloaddition of azomethine ylides with benzylideneacetone

Beilstein Journal of Organic Chemistry, 2014
1,3-Dipolar cycloadditions of isatins, benzylamine and benzylideneacetones were studied to prepare a series of novel spiropyrrolidine-oxindoles – 4′-acetyl-3′,5′-diarylspiro[indoline-3,2′-pyrrolidin]-2-ones and 3′-acetyl-4′,5′-diarylspiro[indoline-3,2 ...
Chuqin Peng, Jiwei Ren, Jun-An Xiao, Honggang Zhang, Hua Yang, Yiming Luo   +5 more
doaj   +1 more source

Site-Selective Modification of a Porpholactone—Selective Synthesis of 12,13- and 17,18-Dihydroporpholactones

Molecules, 2020
The reaction of meso-tetrakis(pentafluorophenyl)porpholactone with azomethine ylides and nitrones affords pyrrolidine-fused and isoxazolidine-fused dihydroporpholactones that display, respectively, isobacteriochlorin- and chlorin-type UV–Vis spectra ...
Ana F. R. Cerqueira, Gustautas Snarskis, Jonas Zurauskas, Samuel Guieu, Filipe A. Almeida Paz, Augusto C. Tomé   +5 more
doaj   +1 more source

A Chemical Framework for Engineering Extracellular Vesicles’ Biointerface to Advance Precision Therapeutics

Advanced Materials, EarlyView.
Extracellular vesicles (EVs) are cell‐derived nanoparticles that mediate intercellular communication through their dynamic biointerfaces. Owing to their intrinsic biological functions, EVs have emerged as promising platforms for biomedical applications.
Leila Pourtalebi Jahromi, Felix Geng, Jan‐Noël Frenzke, Gregor Fuhrmann   +3 more
wiley   +1 more source