2062-29-5Relevant academic research and scientific papers
Eine neue Aminoazirin-Reaktion. Bildung von 3,6-Dihydropyrazin-2(1H)-onen
Hugener, Martin,Heimgartner, Heinz
, p. 172 - 179 (1989)
The reaction of 3-(dimethylamino)-2H-azirines 1 and 2-(trifluoromethyl)-1,3-oxazol-5(2H)-ones 5 in MeCN or THF at 50-80 deg leads to 5-(dimethylamino)-3,6-dihydropyrazin-2(1H)-ones 6 (Scheme 3).Reaction mechanisms for the formation of 6 are discussed: eit
Gas chromatographic and mass spectrometric characteristics of 2-trifluoromethyl-3-oxazol-5-ones. A potentially useful derivative for α-amino acids
Ferrito,Borg,Eagles,Fenwick
, p. 499 - 501 (1979)
The mass spectra of a number of 2-trifluoromethyl-3-oxazol-5-ones, prepared from protein amino acids, have been recorded. The compounds have been separated by gas chromatography using binary column techniques. Analysis of the mass spectra has identified m
Photochemically induced intramolecular radical cyclization reactions with imines
Lefebvre, Corentin,Michelin, Clément,Martzel, Thomas,Djou'Ou Mvondo, Vaneck,Bulach, Véronique,Abe, Manabu,Hoffmann, Norbert
, p. 1867 - 1875 (2018)
The photochemically induced intramolecular hydrogen abstraction or hydrogen atom transfer in cyclic imines 8a,b followed by a cyclization is investigated. Two types of products are observed, one resulting from the formation of a C-C bond, the other from the formation of a C-N bond. A computational study reveals that hydrogen is exclusively transferred to the imine nitrogen leading to a triplet diradical intermediate. After intersystem crossing, the resulting zwitterionic intermediate undergoes cyclization leading to the final product.
Selective synthesis of trisubstituted pyrroles through the reactions of alkynyl Fischer carbene complexes with oxazolones
López, Julio,Velazco-Cabral, Iván,Rodríguez-DeLeón, Eloy,Villegas Gómez, Clarisa,Delgado, Francisco,Tamariz, Joaquín,Arrieta, Ana,Cossío, Fernando P.,Vázquez, Miguel A.
supporting information, p. 538 - 550 (2020/01/30)
An efficient and simple synthesis of novel trisubstituted 1H-pyrroles 4a-qvia 1,3-dipolar cycloaddition of Δ3-trifluoromethyloxazolones 2a-d with both chromium and tungsten alkynyl Fischer carbene complexes (1a-h) is described. An unexpected and unreported -CF3 group elimination process was observed in the pyrrole structure. Our experimental and theoretical data suggested that the metal fragment may be responsible for this phenomenon. The dipolar cycloaddition proceeded efficiently to produce a single regioisomer, which was unambiguously established through NMR and single-crystal X-ray diffraction studies. Nevertheless, the reaction of alkynyl carbenes bearing an α,β,γ,δ-unsaturated moiety with excess oxazolone 2a produced a polycyclic compound 6 speculatively formed through a cascade reaction involving 1,6-, 1,4- and 1,2-nucleophilic addition steps.
Solid Phase Synthesis of (Benzannelated) Six-Membered Heterocycles via Cyclative Cleavage of Resin-Bound Pseudo-Oxazolones
Gr??le, Simone,Vanderheiden, Sylvia,Hodapp, Patrick,Bulat, Bekir,Nieger, Martin,Jung, Nicole,Br?se, Stefan
supporting information, p. 3598 - 3601 (2016/08/16)
A solid supported procedure for the synthesis of benzoxazinones, dihydropyrazinones, quinoxalinones, and dihydrooxazinones using immobilized oxazolones in combination with difunctional nucleophiles as cleavage agent is presented. The scope of the novel me
Photoaddition of alkenes to conjugated α-diketones: Tandem cyclizations leading to tetrasubstituted furans
Mukherjee,Margaretha,Agosta
, p. 3388 - 3391 (2007/10/03)
Photocycloaddition of 9a-c with 2 leads cleanly to tetrasubstituted furans 12a-c, respectively, in yields of ~85%. The reactive triplet is efficiently sensitized by 2-benzoylnaphthalene and quenched by anthracene, indicating that E(T) is in the range 43-58 kcal/mol. A mechanism is proposed involving an alkyl propargyl biradical (as 10) that closes first to a vinyl carbene (as 11) and then to product. Reaction of 9c with 20 furnishes only 22, and this result rules out an alternative mechanism in which the order of steps leading to the carbene is reversed.
UMWANDLUNG VON α-AMINOSAEUREN IN α-DIKETONE UEBER OXAZOLINZWISCHENSTUFEN
Leyendecker, Joachim,Niewoehner, Ulrich,Steglich, Wolfgang
, p. 2375 - 2378 (2007/10/02)
A four step sequence for the conversion of α-amino acids into α-diketones under mild conditions is desribed.
