Open AccessBay-Substituted Thiaza[5]helicenes: Synthesis and Implications on Structural and Spectroscopic Properties
Author(s) -
Mathias Daniëls,
Flip de Jong,
Tom Vandermeeren,
Luc Van Meervelt,
Mark Van der Auweraer,
Wim Dehaen
Publication year - 2019
Publication title -
the journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.2
H-Index - 228
eISSN - 1520-6904
pISSN - 0022-3263
DOI - 10.1021/acs.joc.9b01793
Subject(s) - helicene , substituent , chemistry , indole test , thiophene , palladium , stereochemistry , photochemistry , molecule , catalysis , organic chemistry
A series of bay-substituted thiaza[5]helicenes was synthesized to investigate the effect of different substituents on the properties of these helicenes. These thiaza[5]helicenes with different substituents were prepared in a straightforward manner through indole- and benzo[ b ]thiophene synthesis, palladium-catalyzed Suzuki coupling, oxidative cyclization, and functional group interconversion reactions. We investigated the impact of these different bay area substituents compared to the unsubstituted thiaza[5]helicene on the structural parameters and studied the steady-state electronic spectroscopy of these thiaza[5]helicenes in toluene and acetonitrile. We found that different functional groups influence the solid state structure and spectroscopic properties, but a single substituent in the bay area of a thiaza[5]helicene was not enough to prevent enantiomerization at room temperature.