Chiral Brφnsted acid catalysis has evolved into a powerful synthetic tool in asymmetric synthesis in the past two dec-ades or so.However,despite the broad scope of reactions achieved by chiral Brφnsted acid catalysis,they only involve the activation of a small number of functional groups.Among them,imines and carbonyls are most studied owing to the defined orientation of their lone pairs for hydrogen bonding with acids (Figure 1 a).In contrast,the activation of unsaturated C-C bonds by chiral Brφnsted acids toward asymmetric bond formation is much more challenging.In particular,the activation of C=C bonds has met with limited success.While asymmetric Michael-type addition has been known by indirect activation of C=C bonds (e.g.,ynones,ynoates,Figure 1b),asymmetric control initiated by direct protonation of C=C bonds is rare.This would generate an ion pair between a carbocation and a chiral counteranion(Figure 1a).Different from the strong directionality of hy-drogen bonding,asymmetric induction by counteranion ty-pically relies on much weaker and less directional electrostatic interaction [1].

Xingguang Li;Jianwei Sun

Department of Chemistry,the Hong Kong University of Science and Technology,Clear Water Bay,Kowloon,Hong Kong SAR,China;Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center,Frontiers Science Center for Materiobiology and Dynamic Chemistry,State Key Laboratory of Chemical Engineering,School of Chemistry and Molecular Engineering,East China University of Science & Technology,Shanghai 200237,China

中国科学:化学（英文版）

[1]Xingguang Li;Jianwei Sun-.Asymmetric dearomatization enabled by chiral Brφnsted acid activation of ynamides)[J].中国科学:化学（英文版）,2022(01):3-4

ynamides,ynones,ynoates,carbocation,counteranion,pically

Asymmetric,dearomatization,enabled,by,chiral,Br,nsted,activation,Chiral,catalysis,has,evolved,into,powerful,synthetic,tool,asymmetric,synthesis,past,two,dec,ades,so,However,despite,broad,scope,reactions,achieved,they,only,involve,small,number,functional,groups,Among,them,imines,carbonyls,most,studied,owing,defined,orientation,their,lone,pairs,hydrogen,bonding,acids,Figure,In,contrast,unsaturated,bonds,toward,formation,much,more,challenging,particular,limited,success,While,Michael,type,addition,been,known,indirect,1b,control,initiated,protonation,rare,This,would,generate,between,1a,Different,from,strong,directionality,induction,relies,weaker,less,electrostatic,interaction

0.549676