A general method to diverse cinnolines and cinnolinium salts

Area of Science:

• Organic Chemistry
• Catalysis
• Heterocyclic Chemistry

Background:

• Cinnoline and cinnolinium frameworks are important nitrogen-containing heterocycles with diverse applications.
• Existing synthetic methods for these compounds can be limited in scope or efficiency.

Purpose of the Study:

• To develop a highly efficient and general method for synthesizing cinnolines, cinnolinium salts, and polycyclic cinnolinium salts.
• To explore the utility of rhodium(III) catalysis in C-H activation/cyclization reactions involving azo compounds and alkynes.

Main Methods:

• Rhodium(III)-catalyzed oxidative C-H activation/cyclization reaction.
• Utilized azo compounds and alkynes as key starting materials.
• Optimization of reaction conditions for efficiency and generality.

Main Results:

• Successfully established a method for preparing cinnolines, cinnolinium salts, and polycyclic cinnolinium salts.
• Demonstrated the unprecedented capacity to create both cinnoline and cinnolinium frameworks in a single methodology.
• Achieved high efficiency and generality in the synthesis.

Conclusions:

• The developed rhodium(III)-catalyzed reaction provides a powerful and versatile tool for accessing cinnoline and cinnolinium scaffolds.
• This methodology expands the synthetic repertoire for nitrogen-containing heterocycles.
• Highlights the potential of C-H activation strategies in complex molecule synthesis.