New examples of specific base catalysis in mononuclear rearrangements of heterocycles found via a designed modification of the side chain structure

To select suitable candidates for the occurrence of specific-base-catalysis in MRH of (Z)-hydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole we have designed a modification of the side-chain structure by linking a strong electron-withdrawing system to the hydrazono group. Thus we have synthesized the (Z)-semicarbazone (3d), the (Z)-phenylsemicarbazone (3e), and the (Z)-acetylhydrazone (3f) of the above oxadiazole and examined their kinetic behavior in dioxane/water in a large range of proton concentrations (pS + 4.0 14.5). In all the pS+ range examined only a base-catalyzed process has been evidenced (no uncatalysed path occurs). The behavior at the largest pS+ values (the reactivity tends t…

Effect of linear 5-alkyl substituents on the rearrangement rate of the Z-phenylhydrazones of some 5-alkyl-3-benzoyl-1,2,4-oxadiazoles

Z-Phenylhydrazones of 3-benzoyl-1,2,-oxadiazole: investigation of behaviour in solution and in the gas phase.

Studio cinetico della trasposizione di Z-fenilidrazoni polisostituiti del 3-benzoil-5-fenil-1,2,4-ossadiazolo nei corrispondenti 2-aril-5-fenil-1,2,3-triazoli in H2O/Diossano

Beta-cyclodextrin as host for the rearrangement of some Z-hydrazones of 3-benzoyl-5-X-1,2,4-oxadiazoles.

Trasposizioni eterocicliche mononucleari. Applicazione dell'equazione di Fujita-Nishioka alla reattività di Z-fenilidrazoni di- e poli-sostituiti del 3-benzoil-5-fenil-1,2,4-ossadiazolo.