Metal-Ligand Cooperative Proton Transfer as an Efficient Trigger for Rhodium-NHC-Pyridonato Catalyzed gem-Specific Alkyne Dimerization

Galiana-Cameo M. (Universidad de Zaragoza) ; Urriolabeitia A. (Universidad de Zaragoza) ; Barrenas E. ; Passarelli V. (Universidad de Zaragoza) ; Pérez-Torrente J.J. (Universidad de Zaragoza) ; Di Giuseppe A. ; Polo V. (Universidad de Zaragoza) ; Castarlenas R.

Resumen: The mononuclear square-planar Rh{¿2-X, N-(Xpy)}(¿2-coe)(IPr) (X = O, NH, NMe, S) complexes have been synthesized from the dinuclear precursor [Rh(µ-Cl)(IPr)( ¿2-coe)]2 and the corresponding 2-heteroatom-pyridinate salts. The Rh-NHC-pyridinato derivatives are highly efficient catalysts for gem-specific alkyne dimerization. Particularly, the chelating N, O-pyridonato complex displays turnover frequency levels of up 17 000 h-1 at room temperature. Mechanistic investigations and density functional theory calculations suggest a pyridonato-based metal-ligand cooperative proton transfer as responsible for the enhancement of catalytic activity. The initial deprotonation of a Rh-p-alkyne complex by the oxo-functionality of a ¿1-N-pyridonato moiety has been established to be the rate-limiting step, whereas the preferential protonation of the terminal position of a p-coordinated alkyne accounts for the exclusive observation of head-to-tail enynes. The catalytic cycle is closed by a very fast alkenyl-alkynyl reductive elimination. © 2021 American Chemical Society.

Idioma: Inglés

DOI: 10.1021/acscatal.1c00602

Año: 2021

Publicado en: ACS CATALYSIS 11, 12 (2021), 7553-7567
ISSN: 2155-5435

Factor impacto JCR: 13.7 (2021)

Categ. JCR: CHEMISTRY, PHYSICAL rank: 19 / 165 = 0.115 (2021) - Q1 - T1

Factor impacto CITESCORE: 20.8 - Chemical Engineering (Q1)

Factor impacto SCIMAGO: 4.202 - Chemistry (miscellaneous) (Q1) - Catalysis (Q1)

Financiación: info:eu-repo/grantAgreement/ES/DGA-FSE/E42-20R
Financiación: info:eu-repo/grantAgreement/ES/MECD/FPU17-05417
Financiación: info:eu-repo/grantAgreement/ES/MICINN-FEDER/PID2019-103965GB-I00
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PGC2018-099383-B-I00
Financiación: info:eu-repo/grantAgreement/ES/MINECO/IJCI-2015-27029

Tipo y forma: Article (Published version)

Área (Departamento): Área Química Inorgánica (Dpto. Química Inorgánica)
Área (Departamento): Área Química Física (Dpto. Química Física)