Synthesis Of Alkenyl Nitriles And Pyrazolopyrimidines

Alkenyl nitriles are widely used as pharmaceuticals and agrochemicals due to their biological activity,such as entacapone for Parkinson’s disease,anti-cancer agent trichloroadamantane,and herbicide 2-cyano-3-(substituted)acrylates.In addition,cyano groups serve as a useful synthetic precursor that can be further converted into the desired functional groups such as amines,carbonyls,amides,and carboxylic acids.The synthesis of alkenyl nitrile compounds has been reported extensively,however,most of these methods use expensive transition metal catalysts,higher reaction temperature,longer reaction time,and poorer yield.Therefore,it is still very important to seek a simpler,more economical and more environmentally friendly method for preparing alkenyl nitrile compounds.Pyrazolopyrimidines and related fused heterocycles have been found to have significant pharmacological activities,such as antibacterial,antifungal,antitumor,herbicidal and antiviral,and can be effective inhibitors of inflammatory mediators in intact cells..In addition,some novel pyrazolopyrimidine derivatives determine the properties of antioxidants and play an important role in many degenerative diseases or chronic diseases such as atherosclerosis and cancer.Therefore,these structures are important synthetic targets for bioorganic chemists and the synthesis of novel pyrazolopyrimidine derivatives is of particular interest to organic and pharmaceutical chemists.Based on the reported literature,the methods for synthesizing alkenyl nitriles via C-CN bonds construction without transition metal catalysts and for synthesizing pyrazolo[1,5-a]pyrimidines via tandem reaction have been studied.The simpler,more efficient synthetic methods have been developed.This paper is mainly divided into three chapters:Chapter 1: The application and synthesis of alkenylnitriles and pyrazolopyrimidines are reviewed.Chapter 2: The cyanation of 3-benzylideneindolin-2-one was conducted using benzoyl cyanide as cyanating agent under air conditions to give the corresponding alkenyl nitrile compounds.This method has advantages of no use ofprecious metal catalysts,high yield,simple workup procedure,and high stereoselectivity.Chapter 3: 7-Arylethyl-5-arylpyrazolo[1,5-a]pyrimidines were synthesized via the tandem reaction of aza-Michael addition/nucleophilic addition/oxidation in the presence of a catalytic amount of KOH by reactions of 3-aminopyrazole and dienones.The method has advantages of simple procedure,wide substrate scope and high yield.The gram-grade reaction can also be conducted in good yield.