title: Asymmetric Annulation of Donor-Acceptor Cyclopropanes with Dienes.
abstract: An efficient [4 + 3] cycloaddition reaction of D-A cyclopropanes with dienes has been successfully developed. The reaction proceeds well with various dienolsilyl ethers in the presence of Lewis acid, delivering a variety of cycloheptenes and [n,5,0]carbobicycles with excellent stereoselectivity. The asymmetric version of this reaction is also realized using a newly designed chiral Cy-TOX ligand, providing a new approach to access optically active cycloheptenes and [n,5,0]carbobicycles. Mechanisic study reveals that the reaction involves a stepwise pathway, which undergoes an unusual ring opening of five-membered [3 + 2] intermediate and sequential intramolecular cyclization to afford the thermodynamically stable [4 + 3] annulation product.
authors.affiliation: ‡State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Xu
authors.affiliation: ‡State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China.
authors.forename: Jiang-Lin
authors.initials: JL
authors.lastname: Hu
authors.affiliation: ‡State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China.
authors.forename: Lijia
authors.initials: L
authors.lastname: Wang
authors.affiliation: ‡State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China.
authors.forename: Saihu
authors.initials: S
authors.lastname: Liao
authors.affiliation: ‡State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China.|§Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Tang
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D061565:Cycloaddition Reaction; D003508:Cycloheptanes / Q000138:chemical synthesis* / Q000737:chemistry; D003521:Cyclopropanes / Q000737:chemistry*; D058116:Lewis Acids / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D001643:Bridged Bicyclo Compounds; D003508:Cycloheptanes; D003521:Cyclopropanes; D058116:Lewis Acids