Flow-Enabled, Modular Access to α,α-Difluoromethylene Amines

Area of Science:

• Medicinal Chemistry
• Fluorine Chemistry
• Organic Synthesis

Background:

• The alpha,alpha-difluoromethylene amine (NCF2R) motif is valuable in medicinal chemistry.
• Existing methods for synthesizing NCF2R compounds are often impractical or lack modularity.

Purpose of the Study:

• To develop a safe, scalable, and modular flow-based strategy for generating NCF2R anions.
• To enable the late-stage installation of the CF2 group under mild conditions.

Main Methods:

• Utilized a packed-bed microreactor with caesium fluoride for on-demand generation of NCF2R anions.
• Employed a flow-based strategy for efficient synthesis and diversification.

Main Results:

• Successfully generated NCF2R anions safely and scalably.
• Demonstrated late-stage installation of the CF2 group, avoiding hazardous reagents and minimizing waste.
• Achieved diversification through carboxylic acid, sulfonamide, and electrophile points, accessing a broad range of NCF2R compounds.
• Confirmed tolerance of various functional groups and compatibility with downstream reactions.

Conclusions:

• The developed flow chemistry protocol provides a versatile platform for incorporating NCF2 motifs.
• This method expands synthetic accessibility for NCF2R compounds in medicinal and fluorine chemistry.
• The strategy supports late-stage functionalization of complex scaffolds and is compatible with cross-coupling reactions.