Synthesis of Diindolocarbazoles by Cadogan Reaction: Route to Ladder Oligo(p-aniline)s
摘要:
Symmetric and nonsymmetric diindolocarbazoles were successfully synthesized for the first time by a Cadogan ring closure using N-alkyl-2,7-disubstituted carbazole precursors. Cyclization reaction on N-alkyl-2,7-di(2'-nitrophenyl) carbazole derivatives is not regioselective and produced a separable mixture of symmetric and nonsymmetric diindolocarbazoles. A carbazole derivative with methyl protective groups at the 1- and 8-positions was therefore used to obtain a symmetric ladder oligo-(p-aniline) (compound 22). Optical and electrochemical properties of compound 22 indicate that its neutral semiconducting form is stable in air. This novel class of electroactive ladder oligomers should create new opportunities in micro- and nanoelectronics.
Starting with 2,7-dimethoxycarbazole, a N-alkyl-hexafunctionalized carbazole derivative has been synthesized in only three steps with a good overall yield. N-Octyl-1,8-bistrimethylsilyl-3,6-dibromo-2,7-dimethoxycarbazole is a new synthon that could be useful for the synthesis of conjugated polymers or bioactive compounds.
Synthesis of Diindolocarbazoles by Cadogan Reaction: Route to Ladder Oligo(<i>p</i>-aniline)s
作者:Jimmy Bouchard、Salem Wakim、Mario Leclerc
DOI:10.1021/jo049419o
日期:2004.8.1
Symmetric and nonsymmetric diindolocarbazoles were successfully synthesized for the first time by a Cadogan ring closure using N-alkyl-2,7-disubstituted carbazole precursors. Cyclization reaction on N-alkyl-2,7-di(2'-nitrophenyl) carbazole derivatives is not regioselective and produced a separable mixture of symmetric and nonsymmetric diindolocarbazoles. A carbazole derivative with methyl protective groups at the 1- and 8-positions was therefore used to obtain a symmetric ladder oligo-(p-aniline) (compound 22). Optical and electrochemical properties of compound 22 indicate that its neutral semiconducting form is stable in air. This novel class of electroactive ladder oligomers should create new opportunities in micro- and nanoelectronics.
Starting with 2,7-dimethoxycarbazole, a N-alkyl-hexafunctionalized carbazole derivative has been synthesized in only three steps with a good overall yield. N-Octyl-1,8-bistrimethylsilyl-3,6-dibromo-2,7-dimethoxycarbazole is a new synthon that could be useful for the synthesis of conjugated polymers or bioactive compounds.