Thermische und photochemisch induzierte intramolekulare, 1,3‐dipolare Cycloadditionen von 4‐Phenyl‐3‐(2‐allylphenyl)‐sydnon. Vorläufige Mitteilung. 53. Mitteilung über Photoreaktionen

Abstract

Thermal and photochemically induced intramolecular 1,3-dipolar cycloaddition reactions of 4-phenyl-3-(2-allylphenyl)-sydnone SummaryThe title compound 9 was synthesised in the usual way, starting from 2-allylaniline and ethyl 2-bromo-2-phenylacetate, via the nitrosaminacid 8 (Scheme 2). 9 reacts at room temperature with its potential azomethinimine-function in an intramolecular 3)Teil der geplanten Dissertation.Eine ausfuhrliche Mitteilung sol1 in dieser Zeitschrift erscheinen.

Oxadiazoles

“…3,4-Diarylsydnones lose carbon dioxide by UV irradiation or by flash photolysis and give transient nitrile imines, which can be intercepted by external or internal dipolarophiles [67,68]. For example, the photochemically induced reaction of 3,4-diphenylsydnone affords, in the presence of DMAD, the dimethyl 2,5-diphenylpyrazole-3,4,dicarboxylate (61) (Scheme 13.21), which originates from the loss of CO 2 and the addition of the dipolarophile to the dipolar intermediate 60 (Scheme 13.21) [69].…”

Click and Bio-Orthogonal Reactions with Mesoionic Compounds

“…13 Intermediate IIIa further rearranges to the nitrile imine (NI) species Va via successive ring opening and CO 2 extrusion from the diazarene IVa (Scheme 24c). Based on its 1,3-dipole nature, the intermediate Va has been trapped either intramolecularly 189 or intermolecularly 190 to form pyrazoline or pyrazole cycloadducts.…”

Tandem in situ generation and 1,5-electrocyclization of N-hetaryl nitrilimines. A facile methodology for synthesis of annulated 1,2,4-triazoles and their acyclo C-nucleosides

“…Photolysis of sydnones. [52][53][54][55][56][57][58][59] 8. Thermal decomposition of 5-aryl-4-arylazoisoxazoles.…”