Reaction cascades initiated by nucleophilic attack of heteropentalene mesomeric betaine and nitrogen-rich mesoionic tetrazolium-5-amides on electron-deficient unsaturated compounds. Synthesis of novel heterocyclic systems.
The reactions of heteropentalene mesomeric betaine 1 and nitrogen-rich mesoionic tetrazolium-5-amides 4, 11 and 16-18 with electron-deficient unsaturated compounds have been studied. Novel heterocyclic systems, tetrazolo[4,5-a][1,7]benzodiazonine inner salt 2 and 3-oxo-3,7-dihydro-2H-pyrazolo[3,4-b]pyridine 5, have been synthesized by the reactions of dimethyl acetylenedicarboxylate with 1 and tetrazolium-5-anilide 4, respectively, and fully characterized by X-ray crystallography. It has been found that the reactions of other tetrazolium-5-amides are also initiated by the nucleophilic addition of the electron-rich amide nitrogen to the electron-deficient unsaturated compounds.
Synthesis and structural investigations of N(1-methyl-2-carbomethoxyindolyl-3-sulfonyl)-N′-hetarylureas
We have carried out synthetic and physicochemical investigations of N-(1-methyl-2-carbomethoxyindolyl-3-sulfonyl)-N′-hetarylureas which are a new generation of potential herbicides and plant growth regulators.
Competitive cyclisations of singlet and triplet nitrenes. Part I. Cyclisation of 1-(2-nitrenophenyl)pyrazoles
Aus den 1-(2-Nitrophenyl)-imidazolen (I) erhalt man mit Triathylphosphit (II) die Cyclisierungsprodukte (III).