Dearomative Cyclization/Spirocyclization via Electrochemical Reductive Hydroarylation of Nonactivated Arenes

Area of Science:

• Organic Chemistry
• Electrochemistry
• Synthetic Methodology

Background:

• Reductive dearomatization is a key transformation in organic synthesis.
• Developing efficient methods for cyclization of nonactivated arenes remains challenging.

Purpose of the Study:

• To develop a novel electrochemical protocol for reductive dearomatization and subsequent cyclization/spirocyclization.
• To explore the scope and limitations of this new synthetic strategy.

Main Methods:

• Electrochemical cyclization/spirocyclization via reductive dearomatization.
• Utilizing a simple undivided electrochemical cell.
• Employing nonactivated arenes such as N-substituted indoles, indole-3-carboxamide derivatives, and iodo-substituted benzamides.

Main Results:

• Successful synthesis of 50 diverse indolines, spirocyclizative hydroarylation products, and phenanthridinones.
• Demonstrated high atom efficiency, broad substrate scope, and excellent selectivity.
• Achieved intramolecular addition of aryl radicals to aromatic rings.

Conclusions:

• The developed electrochemical protocol offers a powerful and efficient route to complex cyclic and spirocyclic compounds.
• This method provides a versatile platform for accessing valuable indole derivatives and related structures.