Methylene Cyclopropane Compound Reaction Performance Study

This dissertation includes four sections:The first section summarized the synthetic methodology and the recent progress on the studies of Methylenecyclopropane derivatives. The attractive feature of MCPs is their high level of strain due to the exocyclic double bonds. However Methylenecyclopropane derivatives are relatively stable at room temperature. Even some naturally occurring compounds contain a methylenecyclopropane unit. This section gave a survey of various reactions, including transition metal catalyzed reactions of MCPs, Diels-Alder reactions, cycloadditions, radical reactions and isomerizations.In the second section, we focused on the reaction of methylenecyclopropanes (MCPs). Firstly, we found that Pd(PPh₃)₄-catalyzed isomerization of MCPs in acetic acid proceeds smoothly at 80 °C in toluene to give the corresponding 1-substituted or 1,1-disubstituted dienes in good to excellent yields. The plausible mechanism has been disclosed on the basis of deuterium labeling experiment. Then the next part described the Bnansted acid TfOH-mediated reaction of methylenecyclopropanes with various arenes to give the corresponding double-Friedel-Crafts reaction products (cyclized products) under mild conditions. The reaction mechanism is discussed on the basis of deuterium labeling and the control experiments. The last part of this section described the reactions of gem-aryl disubstituted MCPs with diaryl diselenide produced the corresponding ring-opened products l,2-bis(arylselanyl)-3,3-diaryl- cyclobut-1-ene (four-membered ring) in the presence of iodosobenzene diacetate in moderate to good yields.The third section was focused on the preparation and the synthetic methodology of methylidenecyclopropylcarbinols (MCPOLs). In the first part, we prepared some aryl-substituted methylidenecyclopropylcarbinols according to the literature and synthesized alkyl-substituted methylidenecyclopropylcarbinols. In the second part of this section, we found that the reaction of arylmethylidenecyclopropylcarbinols with iodine in the presence of potassium carbonate or diphenyldiselenide in the presence of sulfuryl chloride stereoselectively gives ring-closure product1-iodo-2-aryl-3-oxabicyclo[3.1.0]hexane orl-phenylselenenyl-2-aryl-3-oxabicyclo[3.1.0]hexane in good to high yields at room temperature. The next part described the Pd(PPh₃)₄-catalyzed isomerization of MCPOLs E-1 with acetic acid proceeds smoothly either at room temperature in dioxane to give the...