A highly efficient one-pot synthesis of benzo[g]indazole derivatives has been achieved
through a cascade Suzuki–Miyaura coupling and aldol condensation reaction. Using Pd(OAc)2
and S-Phos as the catalytic system, the reaction delivered excellent yields and showed
broad tolerance for various substituents on 2-formylphenylboronic acids. Moreover,
this method was successfully applied to the synthesis of benzo[g]indazole-5-carbonitrile
and pyrazolo[4,3-h]quinoline-5-carbonitrile derivatives by altering the coupling partners.
This versatile protocol offers a straightforward and effective method for synthesizing
biologically significant heterocyclic compounds.
Key words
benzo[
g]indazoles - Suzuki–Miyaura coupling - aldol condensation - one-pot reaction - 2-formylphenylboronic
acids - pyrazolo[4,3-
h]quinoline
