Development of New Subtituent Introduction Methods Aimed at Undertaking the Totally Efficient Utilization of Aromatic Compounds

点击翻译按钮获取中文摘要

According to the research plan described in the application form, some typical aryl halides as the starting materials were at first selected and prepared. A new, convenient method for the synthesis of aryl iodides was also developed during this work.1. First, as one of the effective methods for the preparation of substituted aromatic compounds, coupling reaction of the halides prepared with terminal alkynes in the pressence of various first-row transition metal catalysts. It was found that copper(I) iodide-triphenylphosphine 1 : 2 complex is highly efficient for the reaction, giving the corresponding coupled products in excellent yields. Spectroscopic study on the reaction mechanism revealed that the active reaction intermediate is copper(I) acetylide coordinated by the phosphine ligand which can react with the halides to give the products. The reaction using vinyl halides in place of aryl halides can also smoothly proceed.2. Second, aryl alkynyl ketones can also be prepared by carrying out the above reaction under carbon monoxide.3. Third, reaction of aryl iodides with alkenes was examined. While simple alkenes could not be employed, enolate anions generated from active methylene compounds was found to smoothly react in the pressence of copper catalysts to give the corresponding coupled products in good yields. This new reaction method was also applied for the synthesis of 2-arylpropionic acids which are known as antiinfalmmatory agents.4. Finally, an efficient synthetic method of 1-aza-1-buten-3-yne derivatives, which are useful materials for preparation of certain heterocyclic compounds such as pyrazoles, by the reaction of aryl-subsituted nitrones with terminal alkynes in the presence of copper-phosphine catalysts. The information on the reactive intermadiate obtained in the study of item 1 prompted us to develop this reaction.