Mn‐Catalyzed Three‐Component Coupling Reactions of Carboxylic Acids, Diazo Compounds, and Tertiary Amines for the Synthesis of β‐Amino Esters

A simple and efficient three‐component coupling reaction of carboxylic acids, diazo compounds, and tertiary amines catalyzed by manganese has been described. This reaction proceeds smoothly under mild conditions to afford various β ‐amino esters in moderate to good yields by using O 2 as the terminal oxidant. In this process, Mn‐based carbene radical, single‐electron transfer, and nucleophilic attack were fused into a reaction system.