Study On The Design,Synthesis And Properties Of Expanded-Porphyrins And Their Derivatives Based On S_NAr Reactions

The acid-catalyzed condensation reaction and the oxidative coupling reaction of multi-pyrrole compounds were widely applied to construct expanded porphyrins and similar macrocyclic systems.Besides,transition-metal catalyzed coupling reactions were also involved in some reports.However,with these classic methods,there are still some porphyrinoid are difficult to obtain,such as smaragdyrin,a pentapyrrolic expanded porphyrin?1.1.0.1.0?.Recently,Song's group reported the synthesis of all-aza smaragdyrin via the double S_NAr reaction of3,5-dibromodipyrromethene boron difluoride?BODIPY?and tripyran.Based upon the work above,this work researched S_NAr reactions for expanded porphyrins.Employing multi-pyrrole compounds and halogenated multi-pyrrole cyanines as reactants,4 kinds of expanded porphyrins were synthesized via S_NAr reactions.Properties of those expanded porphyrins were preliminarily studied.The specific content of the paper is as follows:?1?According to reported procedures,series of synthons were synthesized,including electron-deficient halogenated multi-pyrrin compounds and electron-rich multi-pyrrole compounds.The reactivity of1,14-dibromotripyrrin was also verified;?2?Expanded porphyrins were synthesized with these synthons through S_NAr reaction.The structures of the target compounds were characterized by ¹H NMR,¹³C NMR,and MS spectra.The crystal structures of the typical compounds like 7,10 and 11,were confirmed by x-ray diffraction analysis.?3?Based on the studies above,the factors that affect S_NAr reactions for expanded porphyrins were discussed.Basic properties such as aromaticity,anti-aromaticity and photophysical properties of typical compounds were also discussed.