The Study Of Asymmetric Construction Of Pyrazolone Related Spirocyclic Compound With Organocatalysts

Pyrazolone,as a five-membered lactam compound containing two nitrogens,has been widely studied in recent years due to its high biological activity.In this thesis,we made some researches on the asymmetric synthesis of pyrazolone spirocyclic compounds?Chapter 1: On the basis of introducing the synthetic value of pyrazolone,this chapter summarizes the synthesis difficulties and the development of synthetic methods.Chapter 2: This chapter discusses the researches of spirocyclic compounds in recent years starting from simple unsubstituted pyrazolone substrates.In view of its difficulties,we have applied the strategy of organic bifunctional catalysis,combining the advantage of organic tandem reactions,from readily available substrates,a series of pyrazolinone spirocyclic compounds with high stereoselectivity were synthesized.This reaction has good substrate compatibility,and the synthesized product has three consecutive chiral centers,two of which are quaternary carbon centers.Chapter 3: In this chapter,we discuss a method for synthesizing pyrazolone spirocyclic compounds using a N-Heterocyclic Carbene-catalyzed strategy.In this method,we synthesized a pyrazolone derivative with two consecutive nucleophilic sites as the substrate and ?-bromocinnamaldehyde as the carbene binding precursor.The desired target products could be obtained with excellent stereoselectivities.