NHC-Catalyzed Stereoselective Synthesis Of Functionalized Pyrrolo[3,2-C]Quinolines And Pyrrolo[1,2-a]Indol-4(2H)-ones

The thesis is composed of three parts:(1) In recent years, N-heterocyclic carbenes (NHCs) have been widely employed as organocatalysts in synthetic transformations. The cascade reactions including α,β-unsaturated acylazolium intermediate and α,β-unsaturated aldehyde catalyzed by NHCs are summarized.(2) We have developed an efficient NHC-catalyzed stereoselective Michael-Mannich-lactamization cascade reaction of tosyl-protected o-amino aromatic aldimines and 2-bromoenals for the synthesis of functionalized pyrrolo[3,2-c]quinolines. The products with three consecutive stereogenic centers were obtained in good yields (up to 94%) with excellent diastereo-(>25:1 dr) and enantioselectivities (up to>99% ee) under mild reaction conditions. A gram scale synthesis of functionalized pyrrolo[3,2-c]quinoline and the non-linear effect of the NHC catalyst have also been investigated. In addition, this approach is attractive due to the potential utilization value for efficient synthesis of Martinella alkaloids.(3) We have disclosed NHC-catalyzed homoenolate annulation with mdole-derived chalcones to obtained polycyclic indole derivatives through a Michael-aldol-lactamization cascade sequence. The products with four consecutive stereogeniccenters were obtained in moderate yield (up to 75%) with good diastereo-(up to 20:1 dr) and excellent enantioselectivities (up to>99% ee) under mild reaction conditions. A gram scale synthesis of functionalized tetrahydrocyclopenta[3,4]pyrrolo[1,2-a]indol-4(2H)-one has also been investigated.