Amedeo Mei

Effect of Metal Ions in Organic Synthesis. part XVI. Knoevenagel Condensations of Aldehydes and Tosylhydrazones with 2,4-Pentanedione by Copper (II) Chloride-Catalyzed Reaction

Abstract Based on some of our previous findings on the activity of some metal ions in certain organic reactivities,1 we have now studied the Knoevenagel condensations of aliphatic and aromatic aldehydes or their tosylhydrazone derivatives with 2,4-pentanedione. In the presence of catalytic amounts of anhydrous copper (II) chloride, these compounds react in tetrahydrofuran at room temperature, affording the corresponding alkylidene or arylidene compounds in 48–98% yields.

Conjugated azoalkenes. Part XI. Direct synthesis of substituted pyrazoles and 4-triphenylphosphoranylidene-4,5-dihydropyrazol-5-ones by heterocyclization of some zwitterionic 1,4-adducts between conjugated azoalkenes and triphenylphosphine

Abstract The simple and direct synthesis in good yields of substituted pyrazoles and 4-triphenylphosphoranylidene-4,5-dihydropyrazol-5-ones is reported. These products have been prepared by heterocyclization under different reaction conditions of some 1,5-zwitterionic species obtained from the 1,4-conjugate addition of triphenylphosphine to the azo-ene system of conjugated azoalkenes.

Conjugated azoalkenes. Part IX. New 1-amino-4-triphenylphosphoranylidene-5-oxo-2-pyrrolines or αβ-unsaturated hydrazones by reaction of azoalkenes with carboalkoxymethylene triphenylphosphorane

Abstract New 1-amino-4-triphenylphosphoranylidene-5-oxo-2-pyrrolines or α,β-unsaturated hydrazones have been obtained in good yield under different reaction conditions by Wittig-type reaction of some conjugated azoalkenes with carboalkoxymethylene triphenylphosphorane. The isolation and characterization of 1,4-adduct intermediate showed that the reaction mechanism implicates only 1,6-zwitterionic intermediate without cycloadduct production, as usually suggested for the Wittig reaction. The crystal structure of one of 1-amino-4-tripheny1phosphorany1ide-ne-5-oxo-pyrrolines obtained has been elucidated by X-ray diffraction study, showing the resonance between the neutral and 1,4-dipolar form.

Effect of Metal Ions in Organic Synthesis. Part XXX. Synthesis of New 3-Carbonyl- and 3-Carboxy-1-Alkoxycarbonylaminopyrroles from Reaction Catalyzed by Copper(II) Chloride of Alkoxycarbonylazoalkenes with β-Diketones and β-Ketoesters

Abstract In the course of our previous investigations, we dealt with the direct synthesis of unknown 1-aminopyrroie derivatives, obtained by reaction of some azoalkenes with B-diketones, 8- ketoesters, or B-ketoamides under copper (II) ionscatalysis. 1-9

Conjugated Azoalkenes. Part XVIII. Synthesis of Functionally Substituted 3-Phosphono-1-aminopyrrol-2-ones and Phosphonohydrazones by Reaction of Conjugated Azoalkenes with β-Phosphonocarboxylates

Abstract New 3-diethylphosphono-2,3-dihydro-3,5-dimethyl-4-alkoxycarbonyl-1-aminopyrrol-2-ones and ethyl 2-diethylphosphono-2-methyl-3-alkoxycarbonyl-4-hydrazonopentanoates were obtained from conjugated azoalkenes and triethyl 2-phosphonopropionate. The synthesis of methyl 2-dimethylphosphono-3-alkoxycarbonyl-4-hydrazonopentanoates by reaction between conjugated azoalkenes and trimethyl phosphonoacetate is also reported.

Simple Direct Synthesis of New 1-Heterocyclamino-3-Carbonylaminopyrroles by Reaction of Heterocyclic Azoalkenes with β-Ketoamides

Abstract Pyrrole and several its derivatives have been subjected to extensive chemical investigations, while substituted 1-aminopyrroles remain a class of compounds about which relatively little is known due to the far from trivial problem sposed by their syntheis. In fact, 1-aminopyrroles appear to be prepared mainly by direct reactionfrom conjugated azoalkenes,2 that unfortunately represent a class of relatively little