Cobalt(iii)-catalyzed synthesis of isoquinolines from oximes and alkynes in deep eutectic solvents

A cobalt-catalyzed redox-neutral [4 + 2] annulation of oximes and alkynes in deep eutectic solvents comprising quaternary ammonium compounds and hydrogen bond donors has been developed, the best system being Me3N+CH2CO2-/HOCH(CF3)2. No external oxidizing reagent was required, and only water was generated as the secondary product. The catalytic system can be reused in three consecutive cycles.

Automated summary

A cobalt-catalyzed [4 + 2] annulation reaction of oximes and alkynes was developed in deep eutectic solvents with quaternary ammonium compounds and hydrogen bond donors, where the best system was Me3N+CH2CO2-/HOCH(CF3)2. No external oxidizing reagent was needed, and only water was produced as the byproduct. The catalytic system could be reused for three consecutive cycles.