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Photochemical Approach to the Cyclohepta[ b ]indole Scaffold by Annulative Two‐Carbon Ring‐Expansion
Author(s) -
Tymann Dina Christina,
Benedix Lars,
Iovkova Lyuba,
Pallach Roman,
Henke Sebastian,
Tymann David,
Hiersemann Martin
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202002581
Subject(s) - indole test , ring (chemistry) , chemistry , photochemistry , stereochemistry , organic chemistry
Abstract We report on the implementation of the concept of a photochemically elicited two‐carbon homologation of a π‐donor–π‐acceptor substituted chromophore by triple‐bond insertion. Implementing a phenyl connector between the slide‐in module and the chromophore enabled the synthesis of cylohepta[ b ]indole‐type building blocks by a metal‐free annulative one‐pot two‐carbon ring expansion of the five‐membered chromophore. Post‐irradiative structural elaboration provided founding members of the indolo[2,3‐ d ]tropone family of compounds. Control experiments in combination with computational chemistry on this multibond reorganization process founded the basis for a mechanistic hypothesis.