RT Journal Article T1 Discrete Cu(I) complexes for azide–alkyne annulations of small molecules inside mammalian cells A1 Miguel Ávila, Joan A1 Tomás Gamasa, María A1 Olmos Verge, Andrea A1 Pérez Romero, Pedro José A1 Mascareñas, José L. AB The archetype reaction of “click” chemistry, namely, the copper-promoted azide–alkyne cycloaddition (CuAAC), has found an impressive number of applications in biological chemistry. However, methods for promoting intermolecular annulations of exogenous, small azides and alkynes in the complex interior of mammalian cells, are essentially unknown. Herein we demonstrate that isolated, well-defined copper(I)–tris(triazolyl) complexes featuring designed ligands can readily enter mammalian cells and promote intracellular CuAAC annulations of small, freely diffusible molecules. In addition to simplifying protocols and avoiding the addition of “non-innocent” reductants, the use of these premade copper complexes leads to more efficient processes than with the alternative, in situ made copper species prepared from Cu(II) sources, tris(triazole) ligands and sodium ascorbate. Under the reaction conditions, the well-defined copper complexes exhibit very good cell penetration properties, and do not present significant toxicities. PB Royal Society of Chemistry SN 2041-6520 SN 2041-6539 electrónico YR 2018 FD 2018 LK http://hdl.handle.net/10272/15917 UL http://hdl.handle.net/10272/15917 LA eng NO Miguel-Ávila, J., Tomás-Gamasa, M., Olmos, A., Pérez, P. J., & Mascareñas, J. L. (2018). Discrete Cu(i) complexes for azide–alkyne annulations of small molecules inside mammalian cells. Chemical Science, 9(7), 1947-1952. https://doi.org/10.1039/c7sc04643j NO This work has received financial support from the MINECO (SAF2013-41943-R, SAF2016-76689-R, CTQ2014-52769-C03-01 and CTQ2015-73693-JIN and Orfeo-cinqa CTQ2016-81797-REDC), the Xunta de Galicia (2015-CP082, ED431C 2017/19 and Centro singular de investigacion de Galicia accreditation 20162019, ED431G/09) and the European Union (European Regional Development Fund - ERDF), and the European Research Council (Advanced Grant No. 340055). M. T.-G. thanks the Ministerio de Economia y Competitividad for the Juan de la Cierva-Incorporacion fellowship (IJCI-2015-23210). The authors thank Prof. A. Vidal for his help with the cytometry studies, Dr P. del Pino for his help with the EPR measurements and R. Menaya-Vargas for excellent assistance. DS Repositorio Institucional de la Universidad de Huelva RD 31 may 2026