The Studies Toward Some Annulations In The Chemistry Of Para-Quinone Methides And Indoles

The asymmetric catalytic intermolecular annulation reactions have been recognized as one of the most prevailing and powerful tools for the enantioselective synthesis of highly functionalized chiral cyclic compounds,and it has received extensive attention in the field of organic synthesis.This thesis mainly focuses on the annulation of para-quinone methides(p-QMs)and electron-deficient indoles,leading to the development of four transition metal-catalyzed annulation reactions for effective synthesis a series of functionalized spirocyclic para-dienones and polycyclic indoles.The research contents of this dissertation are mainly divided into the following five parts:Chapter 1: The research progress of para-quinone methide chemistry is described in detail.Chapter 2: Copper-catalyzed(2+3)annulation of para-quinone methides with amino-substituted cyclopropanes is described,affording a stereoselective synthesis of a series of functionalized spirocyclopentyl para-dienones.Notably,the asymmertric version this(2+3)annulation reaction was also examined,and the related study has established the foundation for further exploring the asymmetric annulation reaction of para-quinone methides.Chapter 3: Palladium-catalyzed asymmetric(2+3)annulation reaction of paraquinone methides with Trimethylenemethanes has been developed to regio-and stereoselectively forge a range of highly functionalized spirocyclopentyl para-dienones.Significantly,driven by the significant improvement in the reactivity and enantioselectivity,a novel type of non-C2-symmetric chiral phosphoramidite ligand consisting of an(S)-BINOL framework and L-hydroxyproline-derived amine units has been designed and applied to the current annulation.This reaction not only provides a strategically complementary enantioselective synthesis of functionalized chiral spirocyclopentyl p-dienones but also enriches the chemistry of p-QMs in the design of methodology for asymmetric catalytic(2+3)annulation.Chapter 4: Palladium-catalyzed asymmetric(2+4)annulation reaction of oxoindole-derived para-quinone methides with ?-methylidene-?-valerolactones has been developed to regio-and stereoselectively establish a series of chiral cyclohexadienone-fused cyclohexyl spirooxindoles.Significantly,three highly congested contiguous tetrasubstituted carbon atoms embedded in bispirocyclic skeleton,of which two are vicinal quaternary stereogenic centers.Noteworthy is that the current methodology also constitutes the first exploration of asymmetric catalytic(2+4)annulation forging the six-membered carbocycles in the chemistry of p-QMs.Meanwhile,this reaction could provide an enantioselective access to densely functionalized cyclohexyl spirooxindoles.Chapter 5: Palladium-catalyzed chemoselective(2+3)and(2+4)annulation of 3-nitroindoles with allyl esters has been developed to chemoselectively construct a series of functionalized cyclopenta[b]indoline scaffolds and tetrahydropyran-[b]indoline scaffolds,respectively.