Amine-to-Halogen Exchange Enables an Amine-Acid Etherification.

Area of Science:

• Organic Chemistry
• Synthetic Methodology
• Catalysis

Background:

• Ether synthesis is crucial across pharmaceutical, fragrance, materials, and agrichemical industries.
• Conventional methods for synthesizing certain alkyl ethers can be challenging and limited in scope.
• Accessing diverse chemical structures, including medicinally relevant compounds, remains an ongoing challenge in organic synthesis.

Purpose of the Study:

• To develop a novel and versatile method for direct ether bond formation from readily available aliphatic amines and carboxylic acids.
• To establish a robust etherification reaction suitable for late-stage diversification and building block repurposing.
• To enable straightforward synthesis of medicinally relevant α-deuterated ethers and explore extensions to other nucleophiles.

Main Methods:

• Development of a one-pot etherification reaction involving amine-halogen exchange followed by ester-selective reduction.
• Utilizing free aliphatic amines and carboxylic acids as starting materials.
• Employing high-throughput experimentation, computational studies, and mechanistic investigations to optimize the reaction.

Main Results:

• Successful direct formation of C-(sp3)-O ether bonds from diverse alkyl amines and carboxylic acids.
• Demonstrated suitability for late-stage diversification and building block repurposing, expanding chemical space access.
• Achieved straightforward synthesis of α-deuterated ethers and extended the deamination strategy to phenolic ethers and halide products.
• Identified specific reagents enabling selective ester reduction in the presence of secondary amides, crucial for the one-pot process.

Conclusions:

• The developed amine-acid etherification reaction provides a versatile platform for constructing diverse ethers from abundant feedstocks.
• The methodology offers a powerful tool for synthetic chemists, particularly in drug discovery and materials science.
• The amine-halogen exchange strategy presents a broadly applicable approach for synthesizing various oxygen-containing compounds and halides.