Studies On The Selective Reactions Of Methylenecyclopropane Derivates With Organic Compounds Containing Phosphor, Sulfur Or Selenium Element

Methylenecyclopropanes (MCPs), which are highly strained but readily accessible molecules, are of current interests in synthetic organic chemistry. Relief of their ring strain provides a potent thermodynamic driving force, which facilitates the construction of complex and interesting organic molecules under mild conditions. During the last decade, the investigations of MCPs have been widely reported. Due to their widely applications in synthetic organic chemistry and pharmacy industry, hetero atom contained organic compounds are also very important and have been researched by chemists for a long period. Hence, the investigations on MCPs' reactions with hetero atom contained organic compounds would be a valuable and interesting subject. In this dissertation, we wish to report the studies on MCPs' reactions with organic compounds containing phosphor, sulfur or selenium elements. These include:1.) Backgrounds of the investigations on MCPs and Phosphor, Sulfur Or Selenium contained compounds.2.) Reactions of MCPs and diethyl phosphite. These include free radical additions and electrophilic additions, which might provide an efficient method for the synthesis of diethyl-3,4-dihydro-2-naphthylphosphonates and 3-butenyl ethyl phosphates stereoselectively.3.) Free radical additions of MCPs and benzenethiol, which might provide an convenient method for the synthesis of 3-phenylsylfanyl-1,2-dihydronaphthalenes.4.) Reactions of MCPs and diphenyldiselenide. The experimental result showed that under visible light irradiation, the free radical addition would happen, providing an convenient method for the preparation of 2,4-diphenylselenyl-1-butenes. Further investigations demonstrated that the single electron transfer reaction could happen in the presence of Cu(OAc)₂. The product could be 1-phenylselenyl-cyclobutenes or 2-phenylselenyl-1,3-butadienes under different conditions. An advanced method for the preparation of 2-phenylselenyl-1,3-butadienes was then developed via the selectively oxidation-elimination of the 4-position phenylselenyl of 2,4-diphenylselenyl-1-butenes by urea hydrogen peroxide.5.) Tandem Michael-nucleouphilic addition of 2-cyclopropylidene propionaldehyde with thioamides or selenoamides. This would provide an efficient method for the synthesis of spiro cyclopropyl ring contained heterocycle compounds.6.) The electrophilic additions of allenes were investigated, providing an efficient method for the synthesis of allyl compounds. The enlargements of substrates were made and the electrophilic additions of 1-cyclopropyl allenes were investigated, providing an efficient and stereo selective method for the synthesis of functional conjugated dienes. The selectivity of this reactions depended on the steric hindrance of the electrophilic groups.