Small Molecule Reactive Activity Research

Recently, highly activated small organic molecules has a wide application in organic synthesis and establishment of organic skeletons. It had attracted the interest of chemists and made it focus of chemical research. Highly activated small organic molecules include methylenecyclopropanes (MCPs), vinylidenecyclopropanes (VCPs), allenes, cyclopropyl allenes (CPAs), and recently methylenecyclobutanes (MCBs). Due to their high ringstrain or cumulated C=C bonding character, these highly activated olefins have high reactivity and can undergo a series of interesting reactions under mild conditions, providing convenient methods for the construction of many useful organic structures. So, they are useful building blocks inorganic synthesis. Therefore, this paper had studied three types of activated olefins. The several main achievements in the research are as follow:1. Lewis acid can catalyze Se-Se bond hetero-cleavage and then further additions reactions with methylenecyclopropanes and allenes with high selectivity. This research provides an effective and environment-friendly method for the synthesis of1,1-diphenylselenyl cyclobutanes derivatives and2,3-diphenylselenyl-1-propenes derivatives.2. Investigations on the reactions of methylenecyclobutanes promoted by CAN in air atmosphere. This reaction leads to spirocyclobutyl-1,2-dioxethanes. The products can not be stored for a long time stably, but they can provide the direct evidence for mechanism research.3. Investigations on the electrophilic additions of methylenecyclobutanes with NXS-H2O system. Then aryl-transferring and direct halohydroxylation products can be obtained in high yield. This reaction providing a concise method for the preparation of cyclobutyl ketones derivatives and cyclobutyl alcohols derivatives. Investigations on the difunctional additions of PhI(OAc)2-TBAB to activated olefins catalyzed by palladium acetate. This reaction are highly chemical selective, regio-selective and stereo-selective. This reaction has high application value because it can introduce two different functional groups simultaneously.In conlusion, highly activated organic molecules always undergo a series of interesting reactions with high selectivity and construct many useful organic skeletons that are hard or need multiple steps to build through traditional methods. Hence, highly activated organic molecules are a kind of highly effective synthetic building blocks.