Intramolecular reductive double cyclization of o,o'-bis(arylcarbonyl)diphenylacetylenes: synthesis of ladder pi-conjugated skeletons.
Upon the treatment of bis(arylcarbonyl)diphenylacetylenes with lithium naphthalenide, the carbonyl reduction dominantly occurs over the acetylene reduction. The produced bis(radical anion) intermediate undergoes a synchronous double-radical 5-endo-dig cyclization. This simple reduction procedure produces two intriguing classes of ladder pi-conjugated skeletons, i.e., emissive methylene-bridged stilbenes and dibenzo[a,e]pentalenes regarded as a cyclic 1,4-diphenylbutadiene.
Zhang
Hongyu
H
Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya 464-8602, Japan.
Karasawa
Takashi
T
Yamada
Hiroshi
H
Wakamiya
Atsushi
A
Yamaguchi
Shigehiro
S