A photochemical dehydrogenative strategy for aniline synthesis

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Cross-coupling reactions are vital for synthesizing pharmaceuticals and agrochemicals.
• Current methods for introducing amines onto aromatic rings have limitations in site selectivity and substrate scope.
• Existing approaches often rely on transition-metal catalysis and pre-functionalized aromatic substrates.

Purpose of the Study:

• To develop a new, regioselective method for aniline synthesis.
• To utilize readily accessible cyclohexanones as surrogates for aryl electrophiles.
• To overcome selectivity challenges associated with traditional aromatic functionalization.

Main Methods:

• A non-canonical cross-coupling strategy employing saturated cyclohexanones.
• Condensation of amines with carbonyl groups for site-selective C-N bond formation.
• A photoredox and cobalt catalytic system for subsequent desaturation to form anilines.

Main Results:

• Demonstrated a novel approach for constructing anilines from cyclohexanones.
• Achieved predetermined and site-selective carbon-nitrogen bond formation.
• Successfully applied the method to synthesize commercial medicines and functionalize natural products, steroids, and terpenes.

Conclusions:

• The developed method provides a versatile and regioselective route to anilines.
• This approach bypasses common selectivity issues in aromatic chemistry.
• The protocol is applicable to late-stage functionalization of complex molecules and natural products.