On-Surface Azide-Alkyne Cycloaddition Reaction: Does It Click with Ruthenium Catalysts?
MetadataShow full item record
Funding and Sponsorship
Owing to its simplicity, selectivity, high yield, and the absence of byproducts, the "click"azide-alkyne reaction is widely used in many areas. The reaction is usually catalyzed by copper(I), which selectively produces the 1,4-disubstituted 1,2,3-triazole regioisomer. Ruthenium-based catalysts were later developed to selectively produce the opposite regioselectivity-the 1,5-disubstituted 1,2,3-triazole isomer. Ruthenium-based catalysis, however, remains only tested for click reactions in solution, and the suitability of ruthenium catalysts for surface-based click reactions remains unknown. Also unknown are the electrical properties of the 1,4- and 1,5-regioisomers, and to measure them, both isomers need to be assembled on the electrode surface. Here, we test whether ruthenium catalysts can be used to catalyze surface azide-alkyne reactions to produce 1,5-disubstituted 1,2,3-triazole, and compare their electrochemical properties, in terms of surface coverages and electron transfer kinetics, to those of the compound formed by copper catalysis, 1,4-disubstituted 1,2,3-triazole isomer. Results show that ruthenium(II) complexes catalyze the click reaction on surfaces yielding the 1,5-disubstituted isomer, but the rate of the reaction is remarkably slower than that of the copper-catalyzed reaction, and this is related to the size of the catalyst involved as an intermediate in the reaction. The electron transfer rate constant (ket) for the ruthenium-catalyzed reaction is 30% of that measured for the copper-catalyzed 1,4-isomer. The lower conductivity of the 1,5-isomer is confirmed by performing nonequilibrium Green's function computations on relevant model systems. These findings demonstrate the feasibility of ruthenium-based catalysis of surface click reactions and point toward an electrical method for detecting the isomers of click reactions.
Showing items related by title, author, creator and subject.
Different functionalization of the internal and external surfaces in mesoporous materials for biosensing applications using "click" chemistryGuan, B.; Ciampi, Simone; Le Saux, G.; Gaus, K.; Reece, P.; Gooding, J. (2011)We report the use of copper(I)-catalyzed alkyne-azide cycloaddition reaction (CuAAC) to selectively functionalize the internal and external surfaces of mesoporous materials. Porous silicon rugate filters with narrow line ...
Amino acid bioconjugation via iClick reaction of an oxanorbornadiene-masked alkyne with a MnI(bpy)(CO)3-coordinated azideHenry, L.; Schneider, C.; Mützel, B.; Simpson, Peter; Nagel, C.; Fucke, K.; Schatzschneider, U. (2014)The catalyst-free room temperature iClick reaction of an unsymmetrically 2,3-disubstituted oxanorbornadiene (OND) as a “masked” alkyne equivalent with [Mn(N3)(bpyCH3,CH3)(CO)3] leads to isolation of a phenylalanine ester ...
Optimization of click chemistry of ferrocene derivatives on acetylene-functionalized silicon(100) surfacesCiampi, Simone; Le Saux, G.; Harper, J.; Gooding, J. (2008)The optimization of the reaction conditions for copper-catalyzed azide-alkyne ,click- cyclo-addition reactions used to covalently confine substituted ferrocene derivatives on passivated silicon(100) surfaces is reported. ...