Results 31 to 40 of about 3,120 (207)

Non-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids. [PDF]

Org Lett, 2022
Treatment of 4-(2-hydroaminoalkylidenyl)- and 4-(2-hydroxyalkylidenyl)-substituted isoxazol-5(4H)-ones with catalytic amounts of [RuCl2(p-cymene)]2, without any additive, afforded pyrazole- and isoxazole-4-carboxylic acids, respectively.
Loro C, Molteni L, Papis M, Lo Presti L, Foschi F, Beccalli EM, Broggini G.   +6 more
europepmc   +6 more sources

Stereoselective cycloaddition of 1-glucosyl-1,3-butadienes with tert-butyl 2H-azirine-3-carboxylate, glyoxylates and imines [PDF]

, 2003
Glucosyl dienes 1 have been reacted with the achiral 2H-azirine 4 and with glyoxylates, forming fused structures of type 5 and disaccharide-like compounds 7 with good to excellent selectivity.
M. José Alves, Isabel Almeida, A. Gil Fortes, Víctor de Freitas   +3 more
openalex   +4 more sources

Cycloaddition of methyl 2-(2,6-dichorophenyl)-2H-azirine-3-carboxylate to electron-rich 2-azadienes [PDF]

, 2003
Tert-Butyldimethylsililoxy-2-aza-1,3-butadienes react with 2H-azirine 3 leading to Diels-Alder cycloadducts in moderate yields. The reactions are endo- and regio- selective with the azirine being added by its less hindered face. There is only one product
M. José Alves, M.M. Duraes, A. Gil Fortes   +2 more
openalex   +4 more sources

Chemistry of 1,3-Dioxepins. XVI.1 The Synthesis, Characterization and Crystallographic Analysis of Some Arylsulphanyl-, Arylsulphinyl-, Arylsulphonyl- and Benzoyl- N-Substituted Derivatives of 1a,2,6,6a-Tetrahydro-1H,4H-[1,3]dioxepino[5,6-b]azirines [PDF]

, 2006
Chemo-selective synthesis and characterization of N-[(4-nitrophenyl)sulphanyl]- 2 and N-[(4- nitrophenyl)sulphinyl]- 3 N-[(4-aminophenyl)sulphonyl]- 5 and N-(4-aminobenzoyl)- 7 derivatives of 1a,2,6,6a-tetrahydro-1H,4H-[1,3]dioxepino[5,6-b]azirines ...
Biserka Prugovečki, Marina Marinković, M. Vinković, Miljenko Dumić   +3 more
openalex   +3 more sources

Azirine ligation: fast and selective protein conjugation via photoinduced azirine–alkene cycloaddition [PDF]

Chemical Communications, 2010
We report a new bioorthogonal ligation reaction between p-nitrodiphenylazirine and dimethyl fumarate. This photoinduced azirine-alkene cycloaddition provides a rapid (~2 min) and highly selective route to protein conjugation at neutral pH and room temperature in biological medium.
Reyna K V, Lim, Qing, Lin
openaire   +2 more sources

Synthetic Strategies to Access Fluorinated Azoles. [PDF]

European J Org Chem
This review highlights recent synthetic strategies for introducing fluorine groups (mono‐, di‐, and trifluoromethylation) into 11 major azole classes, identifying research gaps to inform future innovations in materials science, medicinal chemistry, and biomedical research.
El-Gaber MKA, Djugovski M, Huang TY, Adhikari S, Roy S.   +4 more
europepmc   +2 more sources

Acremolin, a stable natural product with an antiaromatic 1H-azirine moiety? A structural reorientation [PDF]

, 2012
Recently, acremolin (4), a novel modified base, was isolated from a marine-derived fungus and claimed to possess a structure with a 1H-azirine moiety. It is shown now that the reported NMR data are not compatible with this antiaromatic heterocycle, which
Klaus Banert, Backes, Nair, Pearson, Palacios, Gilchrist, Rai, Fowler, Wentrup, Miller, Molinski, Salomon, Stapley, Davis, Davis, Regitz, Jacox, Kodama, Maier, Fowler, Anderson, Gilchrist, Anderson, Gilchrist, Atkinson, Gilchrist, Mitchell, Mitchell, Huisgen, Meinwald, Gilchrist, Gilchrist, Wentrup, Thétaz, Wentrup, Clark, Hopkinson, Bock, Alcami, Lathan, Mó, Byun, Malar, Budzelaar, Alcami, Würthwein, Mó, Čársky, Julianti, Günther, Balci, Hesse, Fedtke, Guengerich, Kuśmierek, Lee, Sattsangi, Still, Pretsch, Kalinowski, Isomura, Guillemin   +61 more
core   +5 more sources

Azirine alkylation

Tetrahedron Letters, 1976
Tetrahedron Letters 17 (1976) 1413-1414. doi:10.1016/S0040-4039(00)71270-6 ; Received by publisher: 1975-12-23 ; Harvest Date: 2016-01-04 12:20:50 ; DOI:10.1016/S0040-4039(00)71270-6 ; Page Range: 1413 ...
Department of Chemistry, University of Florida Gainesville, Florida 32611 U.S.A. ( host institution ), Deyrup, James A. ( author ), Szabo, William A. ( author )   +2 more
openaire   +2 more sources

[3 + 2]-Cycloadditions of nitrile ylides after photoactivation of vinyl azides under flow conditions

Beilstein Journal of Organic Chemistry, 2013
The photodenitrogenation of vinyl azides to 2H-azirines by using a photoflow reactor is reported and compared with thermal formation of 2H-azirines. Photochemically, the ring of the 2H-azirines was opened to yield the nitrile ylides, which underwent a [3
Stephan Cludius-Brandt, Lukas Kupracz, Andreas Kirschning   +2 more
doaj   +1 more source

Copper(I)-catalyzed asymmetric decarboxylative Mannich reaction enabled by acidic activation of 2H-azirines

Nature Communications, 2019
Due to their poor electrophilicity, 2H-azirines do not easily react with nucleophiles. Here, the authors show an acidic activation of 2H-azirines by cyanoacetic acid coupling partners affording chiral aziridines containing vicinal tetrasubstituted and ...
Hai-Jun Zhang, Yan-Cheng Xie, Liang Yin
doaj   +1 more source