Zur protonenkatalysierten elektrophilen substitution von 2,3‐dimethylindol mit arylaldehyden: C6‐regioselektivität am indol‐gerüst

Publisher Website
Google Scholar
Abstract
The proton catalyzed reaction of 2,3‐dimethylindole (1) with several arylaldehydes 2 yields the 6,6′bisindolylarylmethanes 5 regioselectively. No mechanistic information about the predominant attack of the aldehydes on the indole nucleus is obtained, because the reaction proceeds too fast to control. The electron‐rich aldehydes, 2,4,6‐trimethoxybenzaldehyde and indole‐3‐carbaldehyde, yield exclusively the 6,6′,6″‐trisin‐dolylmethane 9. The constitutions of all isolated methanes were elucidated by 400 MHz 1H‐nmr spectroscopy.