Calcium-Mediated C–H and C–F Bond Cleavage: Synthesis of Indenes and Perfluorodibenzopentalenes from 1,4-Dilithio-1,3-butadienes
文摘
The development of Ca-mediated reactions is of great importance and is in great demand in both organometallic and organic chemistry. In this paper, we report that calcium iodide efficiently promotes the transformation of various 1,4-dilithio-1,3-butadienes into indenes or perfluorodibenzopentalenes, via an intramolecular C–H or C–F bond cleavage, respectively. In the reaction process, the Ca-induced s-cis/trans configurational isomerization of 1,4-dilithio-1,3-butadienes is followed by the subsequent nucleophilic C–H or C–F bond activation.