Pyridyl-Directed C-H and C-Br Bond Activations Promoted by Dimer Iridium-Olefin Complexes

Boudreault, P.L.T. ; Esteruelas, M.A. ; Mora, E. (Universidad de Zaragoza) ; Oñate, E. ; Tsai, J.Y.

Resumen: Complexes [Ir(μ-Cl)(η2-C8H14)2]2 (1) and [Ir(μ-Cl)(η4-C8H12)]2 (2) promote the pyridyl-directed ortho-CH and ortho-CBr activations of the phenyl substituent of 2-(2-bromophenyl)pyridine. The formed products depend upon the olefin of the dimer, which governs the kinetic preference of the activation. The cyclooctene complex 1 reacts with the substituted heterocycle to give (η2-C8H14)2Ir(μ-Cl)2Ir{κ2-C,N-[C6BrH3-py]}2 (3), in acetone, at room temperature. Treatment of 3 with K(acac) affords Ir(acac)(η2-C8H14)2 (4) and Ir(acac){κ2-C,N-[C6BrH3-py]}2 (5; acac = acetylacetone). Under more severe conditions, 2-ethoxyethanol under reflux, the reaction of 1 with the heterocycle gives a yellow solid, which yields a 5:82:7 mixture of 5, Ir(acac){κ2-C,N-[C6BrH3-py]}{κ2-C,N-[C6H4-py]} (6), and Ir(acac){κ2-C,N-[C6H4-py]}2 (7) by reaction with K(acac). In acetone or toluene, at room temperature, 2-(2-bromophenyl)pyridine breaks the chloride bridges of dimer 2 to form IrCl(η4-C8H12){κ1-N-[py-C6BrH4]} (8), which evolves into IrClBr{κ2-C,N-[C6H4-py]}(η4-C8H12) (9) as a result of the oxidative addition of the ortho-CBr of the phenyl substituent to the metal center. Treatment of 9 with Ag2O in acetylacetone leads to Ir(acac){κ2-C,N-[C6H4-py]}{κ1-C, η2-[C8H12-(C3-acac)]} (10), as a consequence of the replacement of the halides by an O,O-chelate acac ligand and the outside to metal nucleophilic attack of a second acac group to the diene C–C double bond disposed trans to bromide.

Idioma: Inglés

DOI: 10.1021/acs.organomet.8b00500

Año: 2018

Publicado en: Organometallics 37, 21 (2018), 3770–3779
ISSN: 0276-7333

Factor impacto JCR: 4.1 (2018)

Categ. JCR: CHEMISTRY, ORGANIC rank: 11 / 57 = 0.193 (2018) - Q1 - T1
Categ. JCR: CHEMISTRY, INORGANIC & NUCLEAR rank: 5 / 45 = 0.111 (2018) - Q1 - T1

Factor impacto SCIMAGO: 1.473 - Inorganic Chemistry (Q1) - Physical and Theoretical Chemistry (Q1) - Organic Chemistry (Q1)

Financiación: info:eu-repo/grantAgreement/ES/DGA/E06-17R
Financiación: info:eu-repo/grantAgreement/ES/DGA/FEDER
Financiación: info:eu-repo/grantAgreement/ES/DGA/FSE
Financiación: info:eu-repo/grantAgreement/ES/MINECO/CTQ2016-81797-REDC
Financiación: info:eu-repo/grantAgreement/ES/MINECO/CTQ2017-82935-P

Tipo y forma: Artículo (PostPrint)

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