925230-63-3Relevant academic research and scientific papers
Intramolecular Base-Free Catalytic Wittig Reaction: Synthesis of Benzoxepinones
Grandane, Aiga,Longwitz, Lars,Roolf, Catrin,Spannenberg, Anke,Escobar, Hugo Murua,Junghanss, Christian,Suna, Edgars,Werner, Thomas
, p. 1320 - 1329 (2019)
A straightforward two-step synthesis of benzoxepinones was developed via base-free phosphane-catalyzed Wittig reaction. 3-Methyl-1-phenyl-2-phospholene 1-oxide was used as a precatalyst and trimethoxysilane as a reducing agent. Additionally benzoic acid is employed as a catalyst to facilitate the reduction of the phosphane oxide. Mechanistic investigation revealed the formation of a coumarin as a side product, which was identified by 2D NMR experiments. First results of metabolic activity tests on the prepared benzoxepinones are reported.
Microwave-assisted solvent-free intramolecular 1,3-dipolar cycloaddition reactions leading to hexahydrochromeno[4,3-b]pyrroles: scope and limitations
Pospí?il, Ji?í,Potá?ek, Milan
, p. 337 - 346 (2007/10/03)
We report the microwave-assisted solvent-free synthesis of hexahydrochromeno[4,3-b]pyrroles. Intramolecular 1,3-dipolar cycloadditions proceed under these conditions within 15-40 min in 16-84% yields. An influence of the microwave irradiation upon various [3+2] cycloaddition reaction intermediates was studied. Additionally, a scope and limitations of these reactions including an influence of the dipolarophile geometry upon the cycloaddition selectivity and steric demands of the dipole upon its reactivity were also disclosed. These observations led us to postulate a preferable transition state of the reaction. Finally, an influence of the microwave irradiation to the isomerization of activated olefins was also described.
