Construction Of Quaternary Carbon By Trifluoromethylthiolation And Application Of Spirocyclic Pyrrolidine Quaternary Carbon To Asymmetric Reaction

Quaternary carbon centers widely exist not only in a number of natural products and drug molecules,but also in chiral ligands and catalysts.Therefore,construction of quaternary carbon centers in a highly efficient and diverse way especially in a stereoselective manner have been attracting the research interests of chemists.Because of the unique properties,the trifluoromethylthio group(SCF3)shows potential application in pharmaceuticals,agrochemicals,materials science and semipinacol rearrangement reactions have been proven to be one of the most highly efficient methods in the construction of quaternary carbon centers.Thus,it will be of great significance to use trifluoromethylthio reagent in inducing semipinacol rearrangement.During the past two decades,we have been making great efforts to engage in the research of semipinacol rearrangements.This thesis continues the research topic,and we have made further exploration to construct quaternary carbon center.Meanwhile,our group also has accomplished the synthesis of spirocyclic pyrrolidines with quaternary carbon center using semipinacol rearrangements and have utilized this core skeleton to develop various kinds of organic catalysts and chiral metal ligands,most of which have been successfully applied to a number of asymmetric reactions.During the development of chiral metal ligands,spirocyclic pyrrolidine oxazole bidentate ligands(SPDO)have shown promising results in certain enantioselective catalytic reactions,and we have explored these catalysts too.Through further derivation of SPDO catalysts,we have achieved a series of axially chiral arylindole frameworks via Cu/SPDO-catalyzed cross coupling of quinones and indoles.As a result,the content of this thesis mainly includes the following four aspects:1.The advancement of trifluoromethylthiolation.We make a brief introduction of trifluoromethylthiolation and trifluoromethylthio reagents.2.Electrophilic trifluoromethylthiolation/semipinacol rearrangement: preparation of ?-SCF3 carbonyl compounds with ?-quaternary carbon center.The design of the reaction as well as the reaction conditions screening,substrate scope and reaction mechanism are introduced.3.The development of chiral spirocyclic pyrrolidine catalysts is reviewed.This section mainly contains the synthesis and applications of SPD catalysts.4.Construction of axially chiral arylindole frameworks via Cu/SPDO-catalyzed cross coupling of quinones and indoles.We describe the importance of axially chiral arylindole compounds and the research significance,reaction conditions optimizing and substrate scope of the reaction.