| Pyrrolo[2,3-d]pyrimidine is also called 7-azapurine.The skeleton of 7-azapurine is very similar to that of purine,and 7-azapurine are often used as substitutes for typical components of DNA and RNA for nucleic acid sequencing.In addition,pyrrolo[2,3-d]pyrimidine has been proved to act as bactericide,receptor antagonist,enzyme inhibitor and antiviral nucleoside.In this paper,palladium was used to catalyze the C-H arylation of pyrrolo[2,3-d]pyrimidine derivatives.This C-H arylation reaction provides an effective method for the functional modification of pyrrolo[2,3-d]pyrimidine,which has potential significance in pharmaceutical chemistry.(1)In the first chapter,the arylation reactions catalyzed by transition metal or organic metal were summarized,which can also be induced by light or electricity.This chapter introduced the pharmacological activities of pyrrolo[2,3-d]pyrimidine derivatives and the mechanism of action,such as anticancer,antiviral,antidiabetic,anti-inflammatory,anti-hypertensive,antiprotozoal and other biological activities.At the same time,the research progress of C-H functionalization of pyrrolo[2,3-d]pyrimidine in recent years was reviewed.(2)In the second chapter,a“one-pot”arylation reaction catalyzed by palladium for pyrrolo[2,3-d]pyrimidine derivatives was carried out under mild conditions.Firstly,7-methyl-4-phenyl-7H-pyrrolo[2,3-d]pyrimidine was selected as the substrate to investigate the effects of substrate molar ratio,metal catalyst,solvent,reaction temperature and reaction time on the arylation were studied.The reaction conditions were optimized:Ac OH as solvent,7-methyl-4-phenyl-7H-pyrrolo[2,3-d]pyrimidine(1.0 equiv),Ph I(OAc)2(2.0 equiv)and Ph B(OH)2(2.0 equiv),Pd(OAc)2(5 mol%),reaction temperature 80 oC,reaction time 2 h.48 arylation products were synthesized by expanding the substrate,the yield was 53-93%.The results showed that the electronic effect and steric hindrance on the aromatic ring will affect the efficiency of the reaction.The substrates with electron donating group had higher yield than those with electron absorbing group.The substrates with large steric hindrance were not conducive to the reaction.Based on the experimental results,a possible mechanism of C-H arylation was proposed.(3)In Chapter 3,palladium catalyzed C-6 selective C-H arylation of pyrrolo[2,3-d]pyrimidine derivatives was studied.In this chapter,7-methyl-N-phenyl-7H-pyrrolo[2,3-d]pyrimidine-4-amine was used as a substrate to screen the reaction conditions.The factors such as the ratio of materials,the amount of catalyst,solvent,reaction temperature and reaction time were investigated.The optimized reaction conditions was follows:1,4-dioxane as solvent,Ph I(OAc)2(3.0 equiv)and Ph B(OH)2(3.0 equiv),5 mol%Pd Cl2 as catalyst and 110 oC as temperature.The desired products of C-6 selective arylation were obtained in 65-82%yield.The results show that the substrates bearing chlorine or electron withdrawing substituent on benzene ring were easy to biarylation,otherwise the substrateswith fluorine or electron-withdrawing substituent were favourable to selective C-6 arylation.(4)In Chapter 4,the fluorescence properties of tetraphenylethylene(TPE)derived from pyrrolo[2,3-d]pyrimidine structure were studied.It was found that pyrrolo[2,3-d]pyrimidine can enhance the AIE effect of tetraphenylethylene,which has an importantly valuable application in cell fluorescence imaging.In this chapter,we designed and synthesized a novel molecule combined pyrrolo[2,3-d]pyrimidine with TPE,which was subjuected to investigate its AIE properties.The results showed that the fluorescence intensity of TPE-COOH was about 2 times higher than that of TPE-COOH,which demonstrated that pyrrolo[2,3-d]pyrimidine skeleton has a good strengthening effect on the AIE properties of TPE.This study will provide an important research foundation for the development of new structural AIE fluorescent materials. |
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