title: An efficient approach toward formation of polycyclic coumarin derivatives via carbocation-initiated [4+2] cycloaddition and atom-economical photo-irradiated cyclization.
abstract: Facile carbocation-initiated [4+2] cycloaddition of o-anisole-substituted propargyl silyl ethers and ynamides led to the formation of 4-vinylcoumarins. Subsequent intramolecular cyclization of 3-aryl-4-vinylcoumarins afforded polycyclic coumarin derivatives 11,12-dihydronaphtho[1,2-c]chromen-5-ones in excellent yields under mild photo-irradiated conditions established by fluorescence analysis-oriented screening.
authors.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No. 1378, Wenyi West Road, Science Park of HZNU, Hangzhou 311121, P. R. China. caojian@hznu.edu.cn liwenxu@hznu.edu.cn.
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Cui
authors.forename: Zheng
authors.initials: Z
authors.lastname: Xu
authors.forename: Jian
authors.initials: J
authors.lastname: Cao
authors.forename: Zhan-Jiang
authors.initials: ZJ
authors.lastname: Zheng
authors.forename: Li-Wen
authors.initials: LW
authors.lastname: Xu