Reactions of pop-pincer rhodium(I)-aryl complexes with small molecules: Coordination flexibility of the ether diphosphine

Curto, S.G. ; de las Heras, L.A. ; Esteruelas, M.A. ; Oliván, M. ; Oñate, E. ; Vélez, A. (Universidad de Zaragoza)

Resumen: Reactions of the aryl complexes Rh(aryl){3-P, O, P-[xant(PiPr2)2]} (1; aryl = 3, 5-Me2C6H3 (a), C6H5 (b), 3, 5-Cl2C6H3 (c), 3-FC6H4 (d); xant(PiPr2)2 = 9, 9-dimethyl-4, 5-bis-(diisopropylphosphino)xanthene) with O2, CO, and MeO2CC''CCO2Me have been performed. Under 1 atm of O2, the pentane solutions of complexes 1 afford the dinuclear peroxide derivatives [Rh(aryl){2-P, P-xant(PiPr2)2}]2(-O2)2 (2a–2d) as yellow solids. In solution, these species are unstable. In dichloromethane, at room temperature, they are transformed into the dioxygen adducts Rh(aryl)(2-O2){3-P, O, P-[xant(PiPr2)2]} (3a–3d), as a result of the rupture of the double peroxide bridge and the reduction of the metal center. Complex 3b decomposes in benzene, at 50 °C, to give diphosphine oxide, phenol, and biphenyl. Complexes 1 react with CO to give the square-planar mono carbonyl derivatives Rh(aryl)(CO){2-P, P-[xant(PiPr2)2]} (4a–4d), which under carbon monoxide atmosphere evolve to benzoyl species Rh{C(O)aryl}(CO){2-P, P-[xant(PiPr2)2]} (5a–5d), resulting from the migratory insertion of CO into the Rh-aryl bond and the coordination of a second CO molecule. The transformation is reversible; under vacuum, complexes 5 regenerate the precursors 4. The addition of the activated alkyne to complexes 1b and 1d initially leads to the alkyne intermediates Rh(aryl){2-C(CO2Me)''C(CO2Me)}{3-P, O, P-[xant(PiPr2)2]} (6b, 6d), which evolve to the alkenyl derivatives Rh{(E)-C(CO2Me)=C(CO2Me)aryl}{3-P, O, P-[xant(PiPr2)2]} (7b, 7d). The diphosphine adapts its coordination mode to the stability requirements of the different complexes, coordinating cis-2-P, P in complexes 2, fac-3-P, O, P in compounds 3, trans-2-P, P in the mono carbonyl derivatives 4 and 5, and mer-3-P, O, P in products 6 and 7.

Idioma: Inglés

DOI: 10.1139/cjc-2020-0061

Año: 2021

Publicado en: CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE 99, 2 (2021), 127-136
ISSN: 0008-4042

Factor impacto JCR: 1.051 (2021)

Categ. JCR: CHEMISTRY, MULTIDISCIPLINARY rank: 155 / 180 = 0.861 (2021) - Q4 - T3

Factor impacto CITESCORE: 1.9 - Chemical Engineering (Q3)

Factor impacto SCIMAGO: 0.253 - Chemistry (miscellaneous) (Q3) - Catalysis (Q3)

Financiación: info:eu-repo/grantAgreement/ES/DGA/E06-17R
Financiación: info:eu-repo/grantAgreement/ES/DGA/LMP148-18
Financiación: info:eu-repo/grantAgreement/ES/MECD/FPU17-04813
Financiación: info:eu-repo/grantAgreement/ES/MINECO-AEI-FEDER/CTQ2017-82935-P

Tipo y forma: Article (PostPrint)

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