Transition Metal-Catalyzed Direct C(sp³)-H Functionalization Reactions of Aliphatic Carboxylic Acids

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Carboxylic acids are abundant and versatile functional groups.
• Selective C-H bond functionalization is crucial in organic synthesis.
• The carboxylate group can direct C-H activation for site-selective reactions.

Purpose of the Study:

• To provide a comprehensive overview of transition metal-catalyzed C(sp3)-H functionalization reactions directed by carboxylic acids.
• To examine distinct mechanistic pathways and compare their reactivity, challenges, and opportunities.
• To offer insights for future research in carboxylic acid-mediated C-H functionalization.

Main Methods:

• Review of transition metal-catalyzed C(sp3)-H functionalization reactions from 1991-2025.
• Analysis of mechanistic manifolds, reaction design, and substrate scopes.
• Systematic comparison of different functionalization strategies, including radical-mediated approaches.

Main Results:

• Detailed examination of diverse C-H functionalization strategies enabled by carboxylic acids.
• Comparison of mechanistic features and scope of various transition metal catalysts.
• Assessment of current methodologies and identification of research gaps.

Conclusions:

• Carboxylic acid-directed C-H functionalization is a powerful strategy for synthesizing complex molecules.
• Understanding mechanistic diversity is key to developing novel and efficient synthetic methods.
• This review highlights significant advancements and future directions in the field.