Photoinduced decarboxylation reactions - Radical chemistry in water

Intramolecular photodecarboxylation reactions of potassium omega-phthalimid o carboxylates in water or mixtures of water and organic solvents (acetone, acetonitrile) were investigated using an incoherent XeCl excimer radiation source emitting at 308 nm. Electron transfer induced intermolecular additi on of alkyl carboxylates to phthalimides likewise proceeded efficiently und er these conditions. The reactions can be performed in multigram (i.e. 10-3 0 g product) quantities using easiliy available substrates such as glutamic acid (for the synthesis of 3), leucine (for 8, 9) or simple alkyl carboxyl ates (for 11). The advantages of this methodology are: clean and high-yield ing reactions, solvent and waste minimization, water-based processes and ef ficient utilization of photons of defined energy.