LAUSR

Abstract Organometallic catalysis has allowed the development of an impressive number of chemical transformations that could not be achieved using classical methodologies. Most of these reactions have been accomplished in organic solvents, and in many cases in the absence of water, and under air-free conditions. The increasing pressure to develop more sustainable transformations has stimulated the discovery of metal-catalyzed reactions that can take place in water. A particularly attractive extension of this chemistry consists of the use of biological relevant aqueous solvents, as this might set the basis to translate catalytic metal complexes to biological settings. While this research field is in its infancy, along the last ten years there have been an increasing number of reports demonstrating the viability of achieving metal-promoted transformations in biologically relevant contexts. In this review, that does not intend to be comprehensive, we summarize the most significant advances in the area, and highlight some of the more important difficulties that must be faced when trying to design biocompatible organometallic catalysts, such us stability, cell uptake, bioorthogonality and toxicity. We will manly focus on transition metal systems which have been shown to keep their activity in complex aqueous buffers and inside living cells.