Photoaddition of Alkenes to Conjugated α-Diketones: Tandem Cyclizations Leading to Tetrasubstituted Furans1a
摘要:
Photocycloaddition of 9a-c with 2 leads cleanly to tetrasubstituted furans 12a-c, respectively, in yields of similar to 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.
immobilized oxazolones in combination with difunctional nucleophiles as cleavage agent is presented. The scope of the novel method has been demonstrated through subsequent modification of the parent oxazolone scaffold on solid supports using conversions with electrophiles or CuAAC reactions to give functionalized pyrazin-2-ones. The described method allows the synthesis of the target heterocycles in good
Eine neue Aminoazirin-Reaktion. Bildung von 3,6-Dihydropyrazin-2(1H)-onen
作者:Martin Hugener、Heinz Heimgartner
DOI:10.1002/hlca.19890720123
日期:1989.2.1
A New Aminoazirine Reaction. Formation of 3,6-Dihydropyrazin-2(1H)-ones
新的氨基叠氮基反应。3,6-Dihydropyrazin-2(1 H)-ones的形成
Synthesis of Polysubstituted Symmetrical BODIPYs via Fischer Carbene Complexes: Theoretical, Photophysical and Electrochemical Evaluation
作者:Juan Luis Vázquez、Ivan Velazco‐Cabral、Marcos Flores‐Álamo、Gleb Turlakov、Geraldina Rodríguez、Ivana Moggio、Eduardo Arias、Eduardo Peña‐Cabrera、Miguel A. Vázquez
DOI:10.1002/chem.202202446
日期:2022.12.20
Pyrrole polyfunctionalized core is obtained from Fischer alkynyl carbenes and oxazolones and used to obtain highly functionalized symmetric BODIPYs with modulating optoelectronic properties.
In-depth exploration of polysubstituted BOPHYs Dyes: Synthesis, photophysical, electrochemical, and theoretical properties
作者:Juan Luis Vázquez、Edgar Damián-Ascencio、Marcos Flores-Álamo、Gleb Turlakov、Raquel Ledezma、Eduardo Arias、Ivana Moggio、Eduardo Peña-Cabrera、Miguel A. Vázquez
DOI:10.1016/j.dyepig.2023.111682
日期:2023.12
through the cycloaddition reaction between Fischer carbene and oxazolones. The absorption spectra of all compounds present a main peak due to the HOMO-LUMO electronic transition, as supported by the theoretical study. The maximum has large absorption coefficient ε (∼104 M−1cm−1) and is in the green region from 514 to 531 nm, red shifted with respect to unsubstituted BOPHY. The dihedral angle between the