Investication Of Organnocatalytic Synthesis Of Novelchiral Spirocyclic Oxindole Compounds

Spirocyclic oxindoles are key building blocks and intermediates for the synthesis of natural products and biological compounds, which were widely observed in nature, with many biological activities such as anti-tumor, anti-anxiety, anti-inflammatory, antipyretic and analgesic. In recent years, the synthesis and investigation of these kinds of compounds has aroused much more interest of organic and pharmaceutical chemist. Based on our previous studies on organocatalysis and the construction of spirocyclic compounds, this thesis is mainly focused on the organocatalytic synthesis of enantioenriched spirocyclic oxindole derivatives with multiple chiral centers via a rational designed one pot [2+2+2] annulation. Furthermore, Knoevenagel condensation of isatins and ethyl nitroacetates was also studied, and the desired indole alkenes were obtained in good to excellent yields.The main contents of this thesis are as follows:In the first chapter, we introduce the asymmetric organocatalysis and the catalyst involved, elaborated enantioselective synthesis of spirooxindoles via organocascade strategies on the basis of three types of starting materials:1) unsaturated oxindole derivatives; 2) saturated but substituted oxindoles; 3) C3-unsubstituted oxindoles.In the second chapter, we described an organocatalytic tandem reaction for the synthesis of chiral spirocyclic oxindoles with functional diversity through a rational designed [2+2+2] annulation strategy. Chiral amine was used as catalyst in domino reaction, the spirocyclic oxindole hemiaminals were successfully achieved from aliphatic aldehydes and electron deficient olefin oxindoles in good yields and with high diastereoselectivities.At last, Knoevenagel condensation of isatins and ethyl nitroacetates was investigated. The presented method, which employed isatins and containing active a-H compounds as rection substrates, provided a facile access to a new family of various substituent-isatin derivatives with high selectivities and good yields.