Synthesis Of Novel Type Of N-Heterocyclic Compounds Based On Catalytic Aza-Wittig Reaction

It is one of the most powerful method for aza-Wittig reaction to construct C=N double bonds. It can be used under mild reaction conditions and neutral environment by intramolecular or intermolecular fashion to build many kinds of five, six, seven membered N-heterocycles compounds. It can also be used in the synthesis of macromolecular compounds and natural products. Because it is widely used in synthesis, people are very concerned about it. It is one of the hot topics in the study of catalytic organic synthesis in modern organic chemistry. It is more ideal goals for chemists to develop a kind of atom economy, low cost, high benefit of catalytic organic synthesis reaction. Recently, combined with the latest concept of organic synthesis, based on the traditional aza-Wittig reaction, we designed a kind of catalytic aza-Wittig reaction according to proper improvement of conditions, which achieved the whole catalytic reaction by recycling the by-product--Phosphine oxide.3,4-dihydroquinazoline compounds, indazole derivatives is two kind of N-heterocycles compounds. Chemists pay more attention to them because of their unique biological activity, pharmacological activity and potential medicinal value. Quinazoline ring or indazole ring structure unit is widely exists in the natural alkaloid and it is closely related to the life activities of bioactive molecules. There is a very broad application prospects to research on synthesis of this kind of nitrogen heterocyclic compounds.In this paper, we successfully synthesized3,4-dihydro quinazoline compounds, indazole derivatives by the successful application of the catalytic aza-Wittig reaction. And biological activity of indazole derivatives were test. Specific content is as follows:1. Azides1, obtained from2-azidobenzaldehyde, carboxylic acid, primary amine and isocyanide, were used to prepare quinazoline compounds2under catalytic Staudinger/aza Wittig reaction.2. Reaction intermediates azide1, obtained from2-azidobenzaldehyde and methylene compounds, was added into the catalytic system.1H-pyrazolo[1,5-b]-indazol derivatives2was obtained according to nucleophilic addition/electrophilic addition/catalytic aza-Wittig reaction.