New Synthetic Methods For Heterocycles Based On Tandem Reactions Ofα-Carbonylvinyliminophosphoranes

In this dissertation, efficient synthesis routes of more than ninety unreported compounds in seven series were developed via tandem Staudinger/aza-Wittig/cyclization. The desired products can be obtained from readily available starting materials vinyl azides under mild conditions. These are attractive alternative methods for the synthesises of nitrogen-containing heterocycle derivatives. In addition, Butyramide derivatives were synthesized based on the lead compound "carpropamid", a commercial fungicide. The structures of key intermediates and all the target compounds were confirmed by their spectrum data, and single crystals of some compounds verified the proposes structures. It can be summarized as follows:1. The utilization of vinyl azides in the synthetic organic chemistry as amine precursors, synthetic methodologies of1,4-benzodiazepines and2,4,5-trisubstituted-oxazoles, and the latest progress of aza-Wittig reaction were reviewed.2. Butyramide derivatives were designed and synthesized based on the lead compound "carpropamid", a commercial fungicide. The inhibition action of SD are tested for all compounds. In addition, we simulated and compared the synthesized molecules with SD crystal structures.3. A series of1,2,4-triazino[2,3-b]indazoles or3H-1,4-benzodiazepines were obtained by using a domino Staudinger/aza-Wittig/isomerization reaction or tandem Staudinger/aza-Wittig reaction. This new temperature dependent regioselective synthesis discussed here has the potential in synthetic methodology. The structure of1,2,4-triazino[2,3-b]indazoles12and3H-1,4-benzodiazepines14was confirmed by their spectrum data. Furthermore X-ray structure analysis of12i and14j verified the proposed structure. 4. The aza-Wittig reaction between iminophosphorane and acyl chloride was studied.2,4,5-trisubstituted oxazoles17were synthesized surprisingly via a tandem aza-Wittig/Michael/isomeration reaction of vinyliminophosphorane in one-pot fashion. The single crystals of17n were obtained and X-ray structure analysis verified the proposed structure.5. A series of imidazolidine-2-thiones23and thiazolemethanol25derivatives were synthesized by isothiocyanates, which were obtained from vinyliminophosphorane with CS2, and various aliphatic primary and secondary amines.The condition of the cyclization reaction and the spectral properties of the target compounds were studied. X-Ray structure analysis of25b verified the proposed structure.6. Azide esters, obtained from azide alcohols and various acyl chlorides, reacted with triphenyl phosphine to afford the corresponding oxazoles32via sequential Staudinger/intramolecular aza-Wittig/isomerization reaction. The fluorescence properties of these oxazoles derivatives were studied in ethanol, most compounds have reasonable fluorescence level, which makes them good candidates to be used as fluorescent probes.7.4,5-dihydro-3H-benzo[1,4]diazepines35were obstained from a tandem aza-Wittig/Ugi/aza-Wittig reaction in good yields. we then investigated the substitution effect of the steric effect on the Ugi reaction. X-ray structure analysis of35a verified the proposed structure.