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Monoalkylations of different nucleophilic azoles were investigated with the electron-deficient trans-3,3,3-trifluoro-1-nitropropene (1) as alkylating reagent without addition of any catalyst. In each case, the bonding of the alkene at the azole occurs regioselectively at the trifluoromethyl-substituted C atom of the alkene, whereas the azoles react at different positions depending on the electron density of the heterocycles. Thus, 1-methyl-pyrrole (2) reacted with 1 under C-C bond formation giving the two regioisomers 2-(1-trifluoromethyl-2-nitroethyl)-1-methyl-pyrrole (3) (major product) and 3-(1-trifluoromethyl-2-nitroethyl)-1-methyl-pyrrole (4). The less nucleophilic pyrazole (5), 1,2,4-triazole (7), 3-bromo-1,2,4-triazole (9), and 3,5-dibromo-1,2,4-triazole (12) gave exclusively the corresponding N-alkyl azoles 1- (1-trifluoromethyl-2-nitroethyl )-pyrazole (6), 1-(1-trifluoromethyl-2-nitroethyl) -1,2,4-triazole (8), 3-bromo-1- (1-trifluoromethyl-2-nitroethyl)-1,2,4-triazole (10)/5-bromo-1-(1-trifluoromethyl-2-nitroethyl)-1,2,4-triazole (11), and 3,5-dibromo-1-(1-trifluoromethyl-2-nitroethyl)-1,2,4-triazole (13), respectively. The enantiomeric pairs of the chiral monoalkyl-azoles could not be separated. Moreover, we used trans-3,3,3-trifluoro-1-nitropropene (1) as a dienophile in Diels-Alder cycloadditions with cyclopentadiene (14), cyclohexa-1,3-diene (16), and furan (18). Two diastereomeric products (15A/15B, 17A/17B, and 19A/19B), which could not be separated by column chromatography, are formed from each diene. All compounds were characterized by 1H, 13C, and 19F NMR data.

Monoalkylations of different nucleophilic azoles were investigated with the electron-deficient trans-3,3,3-trifluoro-1-nitropropene (1) as alkylating reagent without addition of any catalyst. In each case, the bonding of the alkene at the azole occurs regioselectively at the trifluoromethyl-substituted C atom of the alkene, whereas the azoles react at different positions depending on the electron density of the heterocycles. Thus, 1-methyl-pyrrole (2) reacted with 1 under C-C bond formation giving the two regioisomers 2-(1-trifluoromethyl-2-nitroethyl)-1-methyl-pyrrole (3) (major product) and 3-(1-trifluoromethyl-2-nitroethyl)-1-methyl-pyrrole (4). The less nucleophilic pyrazole (5), 1,2,4-triazole (7), 3-bromo-1,2,4-triazole (9), and 3,5-dibromo-1,2,4-triazole (12) gave exclusively the corresponding N-alkyl azoles 1- (1-trifluoromethyl-2-nitroethyl )-pyrazole (6), 1-(1-trifluoromethyl-2-nitroethyl) -1,2,4-triazole (8), 3-bromo-1- (1-trifluoromethyl-2-nitroethyl)-1,2,4-triazole (10)/5-bromo-1-(1-trifluoromethyl-2-nitroethyl)-1,2,4-triazole (11), and 3,5-dibromo-1-(1-trifluoromethyl-2-nitroethyl)-1,2,4-triazole (13), respectively. The enantiomeric pairs of the chiral monoalkyl-azoles could not be separated. Moreover, we used trans-3,3,3-trifluoro-1-nitropropene (1) as a dienophile in Diels-Alder cycloadditions with cyclopentadiene (14), cyclohexa-1,3-diene (16), and furan (18). Two diastereomeric products (15A/15B, 17A/17B, and 19A/19B), which could not be separated by column chromatography, are formed from each diene. All compounds were characterized by 1H, 13C, and 19F NMR data.

Synthesis and Spectroscopic Properties of Chiral 1,3-Oxazolidines (1S,2S)-2-Amino-1-(p-nitrophenyl)-propan-1,3-diol 2a and the (1R,2R)-configurated isomer 2b react with N-substituted dithiocarbimidic acid diesters and ketenedithioacetals, respectively, to give the 2-substituted chiral 4-hydroxymethyl-5-phenyl-1,3-oxazolidines 4 and 7. N-Carbmethoxy-dithiocarbimidic acid dimethylester yields under the same conditions the isomeric 1,3-oxazolidine 5. On treatment of 4 and 7 with isocynantes crystalline urethanes 9 are formed.

A New Synthesis of Substituted 4-Amino-1, 3-thiazoles In the 5-position substituted 4-amino-2-alkylthio-1, 3-thiazoles are prepared in good yields from N-nitro-amidino-dithiocarbamates 1 and α-halogen-carbonylcompounds or chloracetonitrile. 1 reacts with 1, 3-dichlor-acetone under formation of adequate bis(1, 3-thiazolyl)ketones. According to the same principle the reaction of the dipotassium salt of the N-nitro-amidino-dithiocarbimidic acid 7 with two equivalents of the α-halogen-carbonylcompound yields 4-amino-5-benzoyl-2-(benzoyl-methylthio)-1, 3-thiazoles.

1H-N.M.R. Spectroscopic Investigations on Innermolecular Mobility of Substituted 1,3-Diazabutadienes Two isomerization processes in substituted 1,3-diazabutadienes can be observed by the method of dynamic n.m.r. spectroscopy. From coalescence phenomena the free activation enthalpies ΔG± are determined and discussed with regard to substituent effects and solvent dependency.