Photoinduced metal‐free hydrocarboxylation of allylamines

Herein, we disclose a new photochemical process to prepare γ‐amino acids from allylamines and formic acid salts. The investigated redox‐neutral hydrocarboxylation process produces high yields across a wide range of functionalized allylamine substrates with excellent regioselectivity. The developed operationally simple protocol can be readily scaled with low photocatalyst loading (from 1% up to 0.02 mol%) without the need for any precautions to exclude air or moisture. The mechanistic working model utilizes a thiol‐catalyzed radical chain process, delivering the hydrogen atom and CO2 from formic acid salt across the alkene substrate through the carboxylate radical (CO2•‐), a crucial reactive intermediate.