000118915 001__ 118915
000118915 005__ 20240319081007.0
000118915 0247_ $$2doi$$a10.1021/acs.organomet.2c00246
000118915 0248_ $$2sideral$$a130033
000118915 037__ $$aART-2022-130033
000118915 041__ $$aeng
000118915 100__ $$0(orcid)0000-0001-7341-0033$$aGonzález-Lainez, M.
000118915 245__ $$aCopper-catalyzed azide-alkyne cycloaddition (CuAAC) by functionalized NHC-based polynuclear catalysts: scope and mechanistic insights
000118915 260__ $$c2022
000118915 5060_ $$aAccess copy available to the general public$$fUnrestricted
000118915 5203_ $$aCopper(I) Cu2(µ-Br)2(tBuImCH2pyCH2L)]n (L = OMe, NEt2, NHtBu) compounds supported by flexible functionalized NHC-based polydentate ligands have been prepared in a one-pot procedure by reacting the corresponding imidazolium salt with an excess of copper powder and Ag2O. An X-ray diffraction analysis has revealed that Cu2(µ-Br)2(tBuImCH2pyCH2NEt2)]n is a linear coordination polymer formed by bimetallic Cu(µ-Br)]2 units linked by the lutidine-based NHC-py-NEt2 ligand, which acts as a heteroditopic ligand with a 1¿C-2¿2N, N' coordination mode. We propose that the polymeric compounds break down in the solution into more compact tetranuclear Cu2(µ-Br)2(tBuImCH2pyCH2L)]2 compounds with a coordination mode identical to the functionalized NHC ligands. These compounds have been found to exhibit high catalytic activity in the Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. In particular, Cu2(µ-Br)2(tBuImCH2pyCH2NEt2)]2 efficiently catalyzes the click reaction of a range of azides and alkynes, under an inert atmosphere at room temperature in neat conditions at a very low catalyst loading, to quantitatively afford the corresponding 1, 4-disubstituted 1, 2, 3-triazole derivatives in a few minutes. The cycloaddition reaction of benzyl azide to phenylacetylene can be performed at 25-50 ppm catalyst loading by increasing the reaction time and/or temperature. Reactivity studies have shown that the activation of the polynuclear catalyst precursor involves the alkyne deprotonation by the NHC moiety of the polydentate ligand to afford a copper(I)-alkynyl species bearing a functionalized imidazolium ligand. DFT calculations support the participation of the dinuclear species (CuBr)2(µ-tBuImCH2pyCH2NEt2)], resulting from the fragmentation of the tetranuclear compound, as the catalytically active species. The proposed reaction pathway proceeds through zwitterionic dinuclear intermediates and entails the active participation of both copper atoms, as well as the NHC moiety as an internal base, which activates the reacting alkyne via deprotonation.
000118915 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/BES-2014-069624$$9info:eu-repo/grantAgreement/ES/MICINN-FEDER/PID2019-103965GB-I00$$9info:eu-repo/grantAgreement/ES/MCIU/FPU19-02903$$9info:eu-repo/grantAgreement/ES/DGA-FSE/E42-20R$$9info:eu-repo/grantAgreement/ES/AEI/PGC2018-095953-B-I00
000118915 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000118915 590__ $$a2.8$$b2022
000118915 592__ $$a0.868$$b2022
000118915 591__ $$aCHEMISTRY, ORGANIC$$b16 / 52 = 0.308$$c2022$$dQ2$$eT1
000118915 593__ $$aInorganic Chemistry$$c2022$$dQ1
000118915 591__ $$aCHEMISTRY, INORGANIC & NUCLEAR$$b16 / 42 = 0.381$$c2022$$dQ2$$eT2
000118915 593__ $$aPhysical and Theoretical Chemistry$$c2022$$dQ1
000118915 593__ $$aOrganic Chemistry$$c2022$$dQ1
000118915 594__ $$a6.6$$b2022
000118915 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000118915 700__ $$aGallegos, M.
000118915 700__ $$0(orcid)0000-0001-6089-6126$$aMunárriz, J.
000118915 700__ $$0(orcid)0000-0001-7904-2729$$aAzpiroz, R.
000118915 700__ $$0(orcid)0000-0002-1735-6439$$aPassarelli, V.
000118915 700__ $$0(orcid)0000-0002-0545-9107$$aJiménez, M. V.
000118915 700__ $$0(orcid)0000-0002-3327-0918$$aPérez Torrente, J. J.$$uUniversidad de Zaragoza
000118915 7102_ $$12010$$2760$$aUniversidad de Zaragoza$$bDpto. Química Inorgánica$$cÁrea Química Inorgánica
000118915 773__ $$g41, 15 (2022), 2154-2169$$pOrganometallics$$tOrganometallics$$x0276-7333
000118915 8564_ $$s3804976$$uhttps://zaguan.unizar.es/record/118915/files/texto_completo.pdf$$yVersión publicada
000118915 8564_ $$s2969880$$uhttps://zaguan.unizar.es/record/118915/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000118915 909CO $$ooai:zaguan.unizar.es:118915$$particulos$$pdriver
000118915 951__ $$a2024-03-18-14:45:55
000118915 980__ $$aARTICLE