Dispersion-Controlled Regioselective Acid-Catalyzed Intramolecular Hydroindolation of cis-Methindolylstyrenes To Access Tetrahydrobenzo[cd]indoles was written by Cai, Xiao;Tohti, Anargul;Ramirez, Cristian;Harb, Hassan;Fettinger, James C.;Hratchian, Hrant P.;Stokes, Benjamin J.. And the article was included in Organic Letters in 2019.SDS of cas: 5118-13-8 This article mentions the following:
Readily prepared cis-β-(α’,α’-dimethyl)-4′-methindolylstyrenes undergo acid-catalyzed intramol. hydroindolation to afford tetrahydrobenzo[cd]indoles. Our exptl. and computational investigations suggest that dispersive interactions between the indole and styrene preorganize substrates such that 6-membered ring formation is preferred, apparently via concerted protonation and C-C bond formation. When dispersion is attenuated (by a substituent or heteroatom), regioselectivity erodes and competing oligomerization predominates for cis substrates. Similarly, all trans-configured substrates that we evaluated failed to cyclize efficiently. In the experiment, the researchers used many compounds, for example, 4-Bromobenzo[b]thiophene (cas: 5118-13-8SDS of cas: 5118-13-8).
4-Bromobenzo[b]thiophene (cas: 5118-13-8) belongs to benzothiophene derivatives. Benzothiophene is relatively a stable molecule. The core structure is a part of various pharmaceutical substances and natural products. Its aromaticity makes it relatively stable, although as a heterocycle, it has reactive sites which allow for functionalization.SDS of cas: 5118-13-8
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem