Indium-Catalyzed Annulation of 2-Aryl- and 2-Heteroarylindoles with Propargyl Ethers: Concise Synthesis and Photophysical Properties of Diverse Aryl- and Heteroaryl-Annulated[<i>a</i>]carbazoles
is applicable also to symmetrical dimers such as bithiophene and bifuran derivatives. Mechanisticstudies suggest that the first step is addition reaction initiated by regioselective nucleophilic attack of the C3 of 2-aryl- and 2-heteroarylindoles to the internal carbon atom of the C[triple bond]C bond in propargyl ethers. The next stage is ring-closing S(N)2 process kicking out the alkoxy group and
Brönsted acidic ionic liquid catalyzed synthesis of benzo[a]carbazole from renewable acetol and 2-phenylindoles in a biphasic system
作者:Minghao Li、Fengtian Wu、Yanlong Gu
DOI:10.1016/s1872-2067(19)63370-x
日期:2019.8
Abstract An efficient metal-free strategy for the synthesis of pharmaceutically relevant benzo[a]carbazoles from the derivatives of readily available 2-phenylindole and bio-renewable acetol in an aqueous biphasic system was developed. This protocol employed a sulfone-containing Bronsted acidic ionic liquid as the catalyst, which could be used for five times without a noticeable decrease in its activity