Cp*Rh(?)-Catalyzed Ortho-Halogenation And Ortho-? Extension Of Perylene Diimides (PDIs)

C-H bond activation has become a rapidly developing research field in recent years owing to the advantages of atom economy and step economy,and it also plays a significant role in the late-stage diversification of various complex organic synthesis.Perylene diimide derivatives(PDIs)are a class of important functional molecules with unique properties,such as high fluorescence quantum yield,high electron mobility and so on.Therefore,it is viewed as a kind of organic materials with promising applications in a variety of fields,ranging from OLEDs to field-effect transistors and biomedical sensors.Main synthetic pathways for the modification of PDI are as below:1)alteration of substituents on the amide nitrogen;2)electrophilic-substitution-type halogenations at bay-position on the perylene core and further functionalization;3)direct functionalization at ortho-position on the perylene core.It is noteworthy that the solubility and energy levels of PDI derivatives could be regulated without distortion of the originally planar PDI core by functionalization at ortho-position,which has wider research prospects.Transition metal catalyzed C-H bond activation is one of the most important strategies for the synthesis of ortho-functionalized PDIs.However,those reported transformations are not suitable for large-scale synthesis,which is crucial for highly efficient diversification of PDIs,due to harsh reaction conditions and considerable substrate dependence.In this paper,Rh(III)-catalyzed highly regioselective ortho-iodination reaction of PDI has been developed,and a range of ortho-?-extended PDI derivatives were designed and synthesized based on ortho-iodinated PDI.This dissertation consists of the following two parts:1.Using 3,4,9,10-perylene diimide as substrate,[Cp*RhC12]2 as catalyst and N-iodosuccinimide(NIS)as a source of iodine,highly regioselective tetra-ortho-iodinated PDIs were synthesized via a multigram scale and column chromatography-free protocol.As is of briefness and efficiency,this methodology avoids cumbersome operations and poor atomic economy and step economy in traditional transformations,and provides key precursors for functional dyes.2.Based on the ortho-iodinated PDI,a series of ortho-?-extended PDI derivatives are straightforwardly synthesized through highly regioselective heteroannulations of ortho-alkynyl substituted or ortho-amino substituted PDI derivatives with sulfur,selenium,or nitrogen nucleophiles.In addition,opto-electrochemical study of these novel thiophene-,selenophene-,thiazole-and pyrrole-fused PDIs shows obvious red shift and lower LUMO-HOMO gap.The unique and versatile physical properties demonstrated the significance of this annulation strategy as well as our previous work on Rh(?)-catalyzed direct ortho-iodination of PDIs.