Gutiérrez González, AlejandroMarcos-Atanes, DanielCool, Leonard G.López García, Fernando JoséMascareñas Cid, José Luis2023-06-152023-06-152023Chem. Sci., 2023, 14, 64081478-6524http://hdl.handle.net/10347/30683Cationic cyclopentadienyl Ru(II) catalysts can efficiently promote mild intermolecular alkyne–alkene couplings in aqueous media, even in the presence of different biomolecular components, and in complex media like DMEM. The method can also be used for the derivatization of amino acids and peptides, therefore proposing a new way to label biomolecules with external tags. This C–C bond-forming reaction, based on simple alkene and alkyne reactants, can now be added to the toolbox of bioorthogonal reactions promoted by transition metal catalystseng© 2023 The Author(s). Published by the Royal Society of Chemistry. This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.http://creativecommons.org/licenses/by-nc/3.0/legalcodejournal article10.1039/d3sc01254a1742-2183open access