jo501383v_si_002.cif (21.93 kB)
Diisobutylaluminum Hydride Promoted Cyclization of o‑(Trimethylsilylethynyl)styrenes to Indenes
dataset
posted on 2014-09-05, 00:00 authored by Hidenori Kinoshita, Nobuyoshi Hirai, Katsukiyo MiuraThe
reaction of o-(trimethylsilylethynyl)styrenes with
diisobutylaluminum hydride (DIBAL-H) provides 2-trimethylsilyl-1H-indenes efficiently. The cyclization mechanism involves
regioselective hydroalumination of the alkynyl moiety, geometrical
isomerization of the alkenylaluminums formed, and intramolecular carboalumination.
With substrates bearing a 2-(trimethylsilyl)ethenyl group (R1 = Me3Si, R2 = R3 = H), bis-silylated
benzofulvenes are obtained upon treatment of the reaction mixture
with an excess amount of benzaldehyde.