Synthesis of useful aromatic derivatives of bile acids through Click chemistry
Bile acids are a very important class of natural surfactants, showing
themselves and their derivatives as effective self-assembling materials. The morphology of bile acid derivative aggregates is strongly
dependant upon the substituents present both on the rigid steroid
backbone and on the side chain, making them suitable for applications in
nanochemistry, sensing and drug delivery.
In the last years our group has been involved in a project concerning the
preparation of bile acid derivatives, bearing aromatic subunits on the C-3
of the steroid polycyclic ring. The Cu-promoted cycloaddition (click
reaction) of azides to aromatic alkynes was used as the key-step in
the synthesis of such derivatives, allowing us to synthesize several
different systems, just like salicylaldehyde, precursors of salophene
complexes, able to give self-assembly. The click chemistry
approach was also useful to link the steroid backbone to other kinds of
aromatic subunits, such as ferrocene, allowing us to obtain compounds,
able to chemically modify the surface of carbon electrodes for sensing
applications.