Research On Building Some Phosphorus-indene Skeleton Compounds

While generally natural products possess enormously biological activity. Thus, to develop efficient methods for the construction of the libraries of natural product-like compounds are very important and practically significant. It attracts more and more interests in organic synthesis to efficiently generate small molecules with structural diversity and stereo-chemical diversity.The thesis is mainly focused on developing green, efficient and simple methods to generate the libraries of natural product-like compounds. We chose one of the aspects as the main research direction-Phosphorus indene compound structure.Chapter one: The latest development of the diversity-oriented synthesis(DOS) is briefly reviewed.Chapter two: A cascade cyclic reaction to synthesize phosphorus indene ring compounds starting from 2-(2-(alkynyl)benzylidene)malonate and phosphorus compounds was developed. The reaction was carefully optimized with different alkali bases, mixture solvents, temperatures and the reaction time, thus, a series of phosphorus indene ring compounds and their derivatives were obtained with moderate to good yields(67%-98%) catalyzed by Fe Cl3 in presence of Cs2CO3 using anhydrous acetonitrile. The advantages of this reaction included high efficiency, easy operation, mild reaction conditions, high atom economy and reaction process economy.Chapter three: The unexpected and novel phosphorus-indene skeleton compounds were obtained for the first time during the above cascade cyclic reaction. A thermodynamics migration of carboxylic ester group may occurred by the promotion of Cs2CO3 at high 120 ℃ temperature. The detailed mechanism is ongoing, and the results will be reported in due course.