Enantioselective Formal [4+2] Cycloadditions to 3-Nitroindoles by Trienamine Catalysis: Synthesis of Chiral Dihydrocarbazoles

被引：98

作者：

Li, Yang ^{[1
]}

Tur, Fernando ^{[1
]}

Nielsen, Rune Pagh ^{[1
]}

Jiang, Hao ^{[1
]}

Jensen, Frank ^{[1
]}

Jorgensen, Karl Anker ^{[1
]}

机构：

[1] Aarhus Univ, Dept Chem, DK-8000 Aarhus C, Denmark

来源：

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION | 2016年 / 55卷 / 03期

关键词：

asymmetric catalysis; cycloaddition; heterocycles; organocatalysis; synthetic methods; DIELS-ALDER REACTIONS; ACTIVE CARBAZOLE ALKALOIDS; INDOLES; GENERATION; INDOLE-2,3-QUINODIMETHANES; DERIVATIVES; ALKYLATION; FUNCTIONALIZATION; CYCLIZATION; ACTIVATION;

D O I：

10.1002/anie.201509693

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The first enantioselective formal [4+2] cycloadditions of 3-nitroindoles are presented. By using 3-nitroindoles in combination with an organocatalyst, chiral dihydrocarbazole scaffolds are formed in moderate to good yields (up to 87%) and enantioselectivities (up to 97% ee). The reaction was extended to include enantioselective [4+2] cycloadditions of 3-nitrobenzothiophene. The reaction proceeds through a [4+2] cycloaddition/elimination cascade under mild reaction conditions. Furthermore, a diastereoselective reduction of an enantioenriched cycloadduct is presented. The mechanism of the reaction is discussed based on experimental and computational studies.

引用

页码：1020 / 1024

页数：5

共 63 条

[1] Regioselective Synthesis of Elusive 4,9-Dihydro-1H-Carbazoles by Gold-Catalyzed Cycloisomerization of 3-Allenylmethylindoles [J].