Study On The Synthesis Of Spirals And Indofluorenones By Palladium Catalyzed Tandem Reaction Of Multiyne

The special spirocyclic skeleton contains two vertical rings,which are connected by a four-substituted solid center.Because of its chirality and correlation with medicinal chemistry,it has attracted extensive attention of organic synthesis researchers.Especially,spirocyclic skeletons have been found in many natural products,bioactive molecules and lead compounds.Fluorenone is a very important structural unit with a unique rigid planar biphenyl structure.Some compounds containing fluorenone structure also have important applications in the fields of optics and electronic devices.There have been many reports on the preparation methods of these compounds,but it is still necessary to develop more simple,efficient,green and economic methods.Because of its various reaction sites and high activity,allenes are an important reaction intermediates in tandem reactions.They can be obtained by ring-opening of cyclopropene,isomerization of propargyl,reaction of organic copper reagents and propargyl derivatives or elimination of olefins,and can also undergo cycloaddition,electrophilic and nucleophilic substitution.On the other hand,Schmittel cyclization based on diene structure can effectively construct fluorenone derivatives.This dissertation is mainly based on a series of reactions of propargyl-allene isomerization and Schmittel cyclization,including the following two aspects.1.In the first part of this thesis,we mainly introduce a series of processes including Heck cyclization,alkali-promoted isomerization,and Schmittel cyclization of benzoyl iodobenzene and diacetylene substrates to finally obtain spirocyclic skeleton compounds.The final products are obtained by one-pot method without separation of diene intermediate,and the reaction conditions were mild and the operation was simple,which provided an efficient and economical method for synthesizing spirocyclic compounds.2.The second part of the thesis is also based on allene intermediates.The iodoalkynone reacts with diynes in the first part,and vinyl allenes are obtained by Alder-ene reaction.These intermediates have high reactivity,and indenofluorenone compounds are obtained after Schmittel cyclization.This process has short reaction time,wide application range and good to excellent yield.