Iterative One-Carbon Homologation of Unmodified Carboxylic Acids

Area of Science:

• Organic Chemistry
• Synthetic Methodology
• Photochemistry

Background:

• One-carbon homologation of carboxylic acids is crucial for synthesizing important molecules in chemistry and biology.
• Existing methods like the Arndt-Eistert sequence are often multistep, harsh, or have limited scope.
• A general, direct method for carboxylic acid homologation has been sought for nearly a century.

Purpose of the Study:

• To develop a practical and general method for the direct one-carbon homologation of unmodified carboxylic acids.
• To overcome the limitations of existing homologation strategies.
• To explore new synthetic opportunities through tunable carbon spacer construction.

Main Methods:

• Utilized the photoredox reactivity of nitroethylene.
• Employed visible-light-induced reactions.
• Performed iterative optimization of the reaction conditions.

Main Results:

• Developed a practical visible-light-induced one-carbon homologation of carboxylic acids.
• Demonstrated a tunable strategy for constructing inert carbon spacers.
• The new method offers a direct conversion, avoiding multistep sequences and harsh conditions.

Conclusions:

• The photoredox-catalyzed reaction provides a novel and efficient route for carboxylic acid homologation.
• This method expands the synthetic toolbox for creating diverse molecular structures.
• The tunable nature of the carbon spacers opens avenues for designing novel compounds.