Palladium-Catalyzed Cycloisomerization of 2-Ethynylbiaryls to 9-Methylidene Fluorenes
作者:Hongyu Guo、Sheng Zhang、Xiujuan Feng、Xiaoqiang Yu、Yoshinori Yamamoto、Ming Bao
DOI:10.1021/acs.orglett.2c00534
日期:2022.4.15
presence of weak acid at low temperature to afford 9-methylidene fluorenes in satisfactory to high yields. This new type of cycloisomerization of 2-ethynylbiaryls is operationally simple and scalable and exhibits high functional-group tolerance. Various synthetically useful functional groups, such as halogen atoms, as well as formyl, acetyl, methoxycarbonyl, cyano, and nitro groups, remain intact during