Precipitons are molecular phase tags for chemical separations. They can be switched from a high-solubility to a low-solubility state to facilitate product, reagent, or catalyst isolation. This paper presents the first photoactivated precipiton and demonstrates that this precipiton is an efficient amine scavenging agent in solution-phase syntheses of amides, ureas, and imines. This approach to amine scavenging offers advantages over solid-phase scavenging ...