title: Unique Steric Effect of Geminal Bis(silane) To Control the High Exo-selectivity in Intermolecular Diels-Alder Reaction.
abstract: The unique steric effect of geminal bis(silane) [(R3Si)2CH] allows an exo-selective intermolecular Diels-Alder reaction of geminal bis(silyl) dienes with α,β-unsaturated carbonyl compounds. The approach shows good generality to form ortho-trans cyclohexenes in good yields with high exo-selectivity and high enantioselectivity in some asymmetric cases. The excellent exo-stereocontrol aptitude of (R3Si)2CH group is highlighted by comparing with R3SiCH2 and R3Si groups, which leads to endo-selectivity predominantly. The conformational analysis of dienes suggests that (R3Si)2CH group effectively shields both sides of the diene moiety, ensuring the desired exo-selectivity. Moreover, the geminal bis(silane) can be further functionalized to transform the resulting ortho-trans cycloadducts into useful synthons, which makes the approach hold great potential for organic synthesis.
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System, Ministry of Education, Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University , Chengdu 610041, P. R. China.
authors.forename: Zengjin
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System, Ministry of Education, Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University , Chengdu 610041, P. R. China.
authors.forename: Xinglong
authors.initials: X
authors.lastname: Lin
authors.affiliation: Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University , Chengdu 610064, P. R. China.
authors.forename: Na
authors.initials: N
authors.lastname: Yang
authors.affiliation: Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University , Chengdu 610064, P. R. China.
authors.forename: Zhishan
authors.initials: Z
authors.lastname: Su
authors.affiliation: Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University , Chengdu 610064, P. R. China.
authors.forename: Changwei
authors.initials: C
authors.lastname: Hu
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System, Ministry of Education, Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University , Chengdu 610041, P. R. China.
authors.forename: Peihong
authors.initials: P
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System, Ministry of Education, Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University , Chengdu 610041, P. R. China.
authors.forename: Yanyang
authors.initials: Y
authors.lastname: He
authors.affiliation: Key Laboratory of Drug Targeting and Drug Delivery System, Ministry of Education, Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University , Chengdu 610041, P. R. China.|State Key Laboratory of Biotherapy, West China Hospital, Sichuan University , Chengdu 610041, P. R. China.
authors.forename: Zhenlei
authors.initials: Z
authors.lastname: Song