The Research On Stereoisomerism Effect Of Friedal-Crafts Rection And 2D/3D Gridization Of Difluorenol With Chiral Configuration

Organic cage molecules,called covalent organic polyhedrons?COPs?with well-defined cavity,have aroused wide attentions owing to their unique properties and great potential applications such as gas sorption,host-guest chemistry,catalysis and chemical sensing.Recently,a series of functional,interlocked and chiral organic molecular cages were successfully synthesized and reported.Based on di-tri-and tetratopic precursors,the 20 most probable cage topologies were classified,of which12 have been realized synthetically.So far,organic cage molecules have linked by reversible dynamic covalent bond method such amine/aldehyde condensation into C=N linkages and boronic acid condensation into B-O linkages.However,these cages are poor chemical stability and most of them are prone to decompose when exposed to acid,base,and moisture.In comparison,C-C bond linked organic cage compounds are more desirable because of their high chemical and thermal stability.The final cyclization step of this type of cage compound is achieved by Wittig reaction,Sonogashira coupling,Glaser type condensation reaction,Yamamoto coupling and alkyne metathesis.However,most of the current approaches suffered from complicated process of precursors,low yields,and a large excess of metal catalysts.Therefore,it's a great challenging to synthesize chemically stable,shape-persistent carbon-carbon bond linked molecular cages in a cost-efficient,metal-free,substrate-simple synthetic strategy.Fluorene-based building blocks that exhibit a good expandable capility and become a good molecular design platform to construct complex compounds,due to well-defined bonding sites and flexible types of linkages.Especially 9-position have obvious advantages in terms of sp²-sp³carbon-carbon coupling via Friedel-Crafts?F-C?reaction with high-effeciency and metal-free features.Therefore,fluorene-based Friedel-Crafts?F-C?cyclization is a good strategy to construct cage compounds.In this thesis,we use bifluorene tertiary alcohol?DFOH?as A₂-type building block and electron-rich triphenylamine as B₃-type building block.we report the synthesis of fluorene-based carbon-carbon bond linked Un-Grid-FTPA,2D Grid-FTPA and 3D Grid-FTPA,obtainted through a simple one-pot method in a BF₃·Et₂O-mediated Friedel-Crafts reaction.The slight grid-dependent properties of 3D Grid-FTPA,2D Grid-FTPA and Un-Grid-FTPA were examined by optical and electrochemical tests.3D-Grid-FTPA shown excellent chemical,thermal,and photo stabilities.In addition,the effect of stereoisomers of DFOH possessing two chiral carbons was evaluated to demonstrate that primary reaction mechanism of F-C syntheses is ascribed to the formation of the transient carbocations and is trapped in classical S_N1 reaction leading the configuration of Un-Grid-FTPA,2D Grid-FTPA and 3D Grid-FTPA not to change with different configurational isomer of DFOH.