Derivatization Of Naphthacene And The Application Of Its N-Heterocyclic Carbene Salt In Activation Of Carbon-Nitrogen Bond

Naphthacene,due to its unique planar conjugated structure,has the advantages of wide ultraviolet absorption range,high charge mobility,and ability to occur singlet exciton fission(SF).While It also has the disadvantages of poor solubility,instability in air for oxidation and dimerization,and poor thin-film morphology.Because of its unique photoelectric properties,it is widely used in organic field effect transistor(OFET),organic photovoltaic(OPV),organic light emitting diode(OLED)and other electronic devices.The preparation of naphthacene derivatives has the characteristics of multi-step synthesis,high cost,low yield,and harsh reaction conditions.Therefore,more naphthacene derivatives with low synthesis cost,novel structure,and stability need to be developed.On the one hand,this paper has achieved the laboratory gram-level preparation of naphthacene,and based on the reduction Knoevenagel reaction,a class of naphthacene derivatives with good solubility and high stability,which can be used as electron transport materials,have been synthesized;On the other hand,a class of N-heterocyclic carbene(NHC)salts with tetracene as the backbone was synthesized for the first time and applied to the nickel-catalyzed reduction coupling reaction of amides and alkylpyridine salts to achieve the deaminoacylation of alkylamines.The first section of the first chapter introduces the review in the synthesis and application of naphthacene derivatives.According to the difference of the substituents,the review is introduced from three aspects of electron-rich substituents,electron-deficient substituents and conjugated group connection.The synthesis of benzene derivatives still has limited methods and high cost;Sections 2 and 3 introduce the research progress of carbon-nitrogen bond activation of two types of nitrogen-containing compounds of alkyl quaternary ammonium salts and amides.From this review we know alkylamine can be effectively activated by forming quaternary ammonium salts and pyridine salts.Quaternary ammonium salts were mainly used in the activation of carbon-nitrogen bond of active amines containing benzyl and allyl groups.ordinary alkylamines can be effectively activated through form pyridine salts.The review introduces changing the substituent on the amide nitrogen,which result in the change of the steric hindrance and electron density and the form of non-planar twisted amide,is an effective way to activate the carbon-nitrogen bond of the amide.Besides,more functionalization of alkylamine and amide through carbon-nitrogen bond activation is worthwhile expand.The second chapter introduces the synthesis and characterization of a class of naphthacene derivatives with good solubility and high stability,which can be used as electron transport materials.On the basis of completing the gram-level preparation of naphthacene in laboratory,we achieved the preparation of a class of cyclopenta-fused polycyclic aromatic hydrocarbons(CP-PAH)by reducing Knoevenagel reaction.Compared with naphthacene,the derivative has significantly improved solubility due to non-coplanar branches;the stability is increased due to the CP-PAH structure and electron-withdrawing carbonyl conjugation.Photoelectric property testing and quantum chemical calculations indicate that its HOMO energy level decreases by about 0.3 ev,and the band gap Eg decreases by about 0.5 ev.Optical studies have shown that there is a wide ultraviolet absorption in the range of 300 nm to 600 nm,the maximum fluorescence emission peak is near 600 nm,and the fluorescence quantum yield in toluene is doubled compared to naphthacene by 33%.The electron mobility μe measured by SCLC is 1.6×10-4 cm2/(Vs),indicating that it is suitable as an electron transport material.This work is a useful supplement to the derivatization of naphthacene and provides a reference for exploratory synthesis ofelectron transport materials.In Chapter 3,we developed a nickel-catalyzed reduction coupling reaction of amides and alkyl pyridine salts.In this reaction,for the first time we used N-heterocyclic carbene(NHC)salts with tetracene as the backbone as the ligand precursor.In this work,the formation of pyridine salt is used to activate the carbon-nitrogen bond of the alkylamine,and the twisted amide is used as an acyl reagent to realize the cross-coupling of the two electrophiles.This method can realize the deaminoacylation of both primary and secondary alkylamines,especially the amino acids.The method with mild reaction conditions and good functional group compatibility(compatible with ester groups,indole rings,and sulfonamides)provides a way for the later modification of complex organic amines.Furthermore,this work synthesized a new class of carbene ligand precursors with tetracene as the backbone,and proved that the new carbene salt has catalytic activity in metal-catalyzed coupling reactions.In this work,carbene salt with new structure was synthesized and applied,and the deaminoacylation of alkylamine was realized for the first time.Nevertheless,there are still some difficulties,such as:the method is sensitive to the electron density of the amide aromatic ring and with incompatibility of electron-deficient amides and alkyl amides;the application of new structures of carbene salts in more reactions is to be investigated;compared with normal NHC salts,the advantages are not clear.