The Annulation Reactions Of Para-Quinone Methides With Nitrogen-Containing Synthons

para-Quinone methides(p-QMs)featuring a unique bisvinylogous enone system have received considerable attentions in the development of methodologies in organic synthesis due to its intrinsic electrophilicity.In this thesis,four types of reactions focusing on the annulations of p-QMs with nitrogen-containing synthons have been designed and developed for the efficient synthesis of cyclic compounds having novel structure and potential biological activity.The following four parts are included below.Part ?(chapter 1):The research progress towards the annulation reactions of pQMs is reviewed.Part ?(chapter 2):A novel tandem photo-induced Wolff rearrangement/(4+2)annulation reaction of o-hydroxyphenyl-substitutedp-QMs with diazoketones has been developed for the efficiently diastereoselective synthesis of structurally unique 4-aryl hydrocoumarins and their diastereoisomers.Notably,the present study provides examples on the first exploration of photo reaction in the annulation of ohydroxyphenyl-substitutedp-QMs,and it offers a new perspective for the development of methodology of p-QMs.Part ?(chapter3):An unprecedented tandem(2+2)annulation/retro-4?electrocyclization/imino-Nazarov cyclization reaction of p-QMs and ynamides has been designed and realized for expeditious construction of functionalized aminoindenes through an uncommon structural reconstruction of p-QMs.Based on above tandem annulation,one-pot oxidation protocol has been explored to access the synthetically important indenones.Signifcantly,the(2+2)annulation mode of p-QMs has been investigated for the first time,and this study to some extent enriches the chemistry of p-QMs.Part ?(chapters 4&5):A new type of indolyl-substituted p-QMs has been designed,and two new annulation modes have been explored with different regioselectivity.In chapter 4,a new tandem(2+2)annulation/retro-4?electrocyclization/imino-Nazarov cyclization reaction of indolyl-substituted p-QMs and ynamides has been developed for the effective construction of multi-substituted aminocyclopenta[b]indoles.In chapter 5,a novel(3+2)annulation reaction of indolylsubstituted p-QMs and allenamides has been established to yield structurally unique aminocyclopenta[b]indoles.The unique reactivities of indolyl-substitutedp-QMs have been revealed for the first time in the study of annulation reactions.These investigations to some extent provide a new content in the methodology design of p-QMs.