LAUSR

Chemical (as opposed to light‐induced) activation of caged molecules is a rapidly advancing approach to trigger biological processes. We previously introduced the ruthenium‐catalyzed release of allyloxycarbonyl (alloc)‐protected amines in human cells. A restriction of this and all other methods is the limited lifetime of the catalyst, thus hampering meaningful applications. In this study, we addressed this problem with the development of a new generation of ruthenium complexes for the uncaging of alloc‐protected amines with superior catalytic activity. Under biologically relevant conditions, we achieved a turnover number >300, a reaction rate of 580 m−1 s−1, and we observed high activity in blood serum. Furthermore, alloc‐protected doxorubicin, as an anticancer prodrug, could be activated in human cell culture and induced apoptosis with a single low dose (1 μm) of the new catalyst.