Asymmetric Synthesis Of Axial Chiral Aromatic Hydrocarbons

Axially chiral biaryls are common structural motifs in many natural products with important biological activities.Many of chiral biaryls play important roles in asymmetric catalytic reaction,the core structure of the effective chiral ligands.Therefore,efficient synthesis of axially chiral biaryls has been one of important issues in organic chemistry.The following strategies have been mainly taken to synthesize chial biaryls:?chiral auxiliary-assisted synthesis of chiral biaryls;? Asymmetric catalytic C-C coupling;? Asymmetric oxidative coupling;? Kinetic resolution;?Astoposelectivive transformations on aryl-C single bond into the biaryl axis upon construction of the second arene ring from an aryl-C substituent.Despite significant advances in asymmetric synthesis of chiral biaryls,novel methods are still highly desirable.In our group,we have developed a new intermolecular organo-catalyzed C-C bond froming reaction to generate ?-hydroxyl-?-vinyl carboxylic esters in the presence of aldehydes and ?,?-unsaturated esters.And we demonstrated that binaphthyl compounds could be constructed efficiently via the intramolecular strategy.This novel protocal inherits the merits of Morita-Baylis-Hillman reaction such as atom economy,environmental friendliness,mild reaction conditions,etc.Based on our previous results,we proposed that chiral binaphthyl compounds would be prepared using chiral auxiliary-assisted intramolecular protocol.We did extensive studies and the following topics were covered in this thesis:? Studies toward on the subtrate synthesis;? Discussion of the effects of temperature and type of chiral auxiliaries on the stereoselectivity and yield;? Optimization of the reation condifions and compeletion of the synthesis of twelve chiral binaphthyl compounds,including electron-deficient ones,electron-donating ones,large steric hindrance ones;?Investigation on the conditions for removal of chiral auxiliaries.In this thesis,a novel chiral auxilary-assisted organo-catalyzed asymetric method has been developed for construction of chiral binaphthyl compounds.This method has the advantages,such as environmental friendliness,mild reaction conditions and atom-economy.In addition the chiral auxiliary can be readily removed with the retention of stereoselectivity.