title: Lewis acid catalyzed [2+2] cycloaddition of ynamides and propargyl silyl ethers: synthesis of alkylidenecyclobutenones and their reactivity in ring-opening and ring expansion.
abstract: A family of four-membered enones, polysubstituted alkylidenecyclobutenones, were easily prepared by a Lewis acid catalyzed [2+2] cycloaddition of ynamides and propargyl silyl ethers. This challenging regioselective [2+2] cycloaddition enables the efficient construction and conversion of four-membered enones, which provides high-value and structurally diverse products through the unexpected ring-opening and ring expansion of alkylidenecyclobutenone with Grignard reagents, organolithium, primary amines, and water.
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.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: Jian
authors.initials: J
authors.lastname: Cao
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: Zheng
authors.initials: Z
authors.lastname: Xu
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: Zhan-Jiang
authors.initials: ZJ
authors.lastname: Zheng
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: Yu-Ming
authors.initials: YM
authors.lastname: Cui
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 and State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences (CAS), P. R. China.
authors.forename: Li-Wen
authors.initials: LW
authors.lastname: Xu