title: Asymmetric annulation of 3-alkynylacrylaldehydes with styrene-type olefins by synergetic relay catalysis from AgOAc and chiral phosphoric acid.
abstract: Asymmetric annulation of 3-alkynylacrylaldehydes with 2-hydroxystyrenes has been studied and achieved by synergetic catalysis from AgOAc and chiral phosphoric acid, providing the corresponding multiring products with decent total yields and moderate to excellent enantioselectivities (up to 95% ee). The developed mild multibond-formation cascade reaction involves in situ generation of pyrylium intermediate by Ag(I)-catalyzed alkyne/carbonyl cycloisomerization, counteranion-directed asymmetric oxa [4 + 2]-cycloaddition, and intramolecular nucleophilic substitution.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University , 22 Hankou Road, Nanjing, Jiangsu 210093, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Le
authors.initials: L
authors.lastname: Zhu
authors.forename: Shaozhong
authors.initials: S
authors.lastname: Wang
authors.forename: Zhu-Jun
authors.initials: ZJ
authors.lastname: Yao