Tungsten Oxide Dispersed on Silica as Robust and Readily Available Oxo/Imido Heterometathesis Catalyst

Continuing our investigation of catalytic oxo/imido heterometathesis as novel water-free method for C=N bond construction, we report here the application of classical transition metal oxides dispersed on silica (MOx/SiO2, M=V, Mo, W) as cheap, robust and readily available alternative to the catalysts prepared via Surface Organometallic Chemistry (SOMC). The oxide materials demonstrated activity in heterometathetical imidation of ketones, WO3/SiO2 being the most efficient. We also describe a new well-defined supported W imido complex (≡SiO)W(=NMes)2(Me2Pyr) (Mes=2,4,6-Me3C6H2, Me2Pyr=2,5-dimethylpyrrolyl) and characterize it with SOMC protocols, which allowed us to identify the position of W on the oxo/imido heterometathesis activity scale (Mo Collapse

Key Words

• imido
• imines
• metathesis
• supported catalysts
• tungsten

Collapse

MESH Headings Collapse

Grants

• 19-73-10163 Russian Science Foundation
• 075-00277-24-00 Ministry of Science and Higher Education of the Russian Federation

Collapse

Affiliation(s)

Nikolai S Bushkov A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia
Andrey V Rumyantsev A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia Chemistry Department, Moscow State University, Vorob'evy Gory, 1, 119992, Moscow, Russia
Anton A Zhizhin A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia
Tatyana V Strelkova A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia
Roman A Novikov N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prosp., 47, 119991, Moscow, Russia
Evgenii I Gutsul A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia
Rina U Takazova A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia
Dinara K Kitaeva A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia
Nikolai A Ustynyuk A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia
Pavel A Zhizhko A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia
Dmitry N Zarubin A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia

Collapse

Catalyzed M–C coupling reactions in the synthesis of σ-(pyridylethynyl)dicarbonylcyclopentadienyliron complexes

The reactions between terminal ethynylpyridines, (trimethylsilyl)ethynylpyridines and cyclopentadienyliron dicarbonyl iodide were studied under Pd/Cu-catalyzed conditions to develop a synthetic approach to the σ-alkynyl iron complexes Cp(CO)₂Fe–C Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> C–R (R = ortho-, meta-, para-pyridyl). Depending on the catalyst and reagents used, the yields of the desired σ-pyridylethynyl complexes varied from 40 to 95%. In some cases the reactions with ortho-ethynylpyridine gave as byproduct the unexpected binuclear FePd μ-pyridylvinylidene complex [Cp(CO)Fe{μ₂-η¹(C_α):η¹(C_α)-κ¹(N)-C_α Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> C_β(H)(o-C₅H₄N)}(μ-CO)PdI]. The conditions, catalysts, and reagents that provide the highest yields of the desired σ-pyridylethynyl iron compounds were determined. The methods developed allowed the synthesis of the corresponding σ-4-benzothiadiazolylethynyl complex Cp(CO)₂Fe–CC–(4-C₆H₃N₂S) as well. Eventually, synthetic approaches to σ-alkynyl iron complexes of the type Cp(CO)₂Fe–CC–R (R = ortho-, meta-, para-pyridyl, 4-benzothiadiazol-2,1,3-yl) based on the Pd/Cu-catalyzed cross-coupling reactions were elaborated.

Two approaches were developed for the synthesis of iron σ-pyridylethynyl complexes based on Pd/Cu- and Pd-catalyzed Fe–C coupling reactions.

Catalytic Oxo/Imido Heterometathesis by a Well-Defined Silica-Supported Titanium Imido Complex

Grafting Ti(=NtBu)(Me₂ Pyr)₂ (py)₂ (Me₂ Pyr= 2,5-dimethylpyrrolyl, py=pyridine) onto the surface of silica partially dehydroxylated at 700 °C gives the well-defined silica-supported Ti imido complex (≡SiO)Ti(=NtBu)(Me₂ Pyr)(py)₂ , which is fully characterized by IR and solid-state NMR spectroscopy as well as elemental and mass balance analyses. While stoichiometric imido-transfer reactivity is typical for Ti imides, the obtained surface complex is unique in that it enables catalytic transformations involving Ti imido and oxo intermediates. In particular, it efficiently catalyzes imidation of carbonyl compounds with N-sulfinylamines by oxo/imido heterometathesis.

Crystal structure of μ-carbonyl-1:2κ2C:C-carbonyl-1κC-(1η5-cyclo-penta-dien-yl)iodido-2κI-[μ-2-(pyridin-2-yl)ethene-1,1-diyl-1κC1:2κ2N,C1]ironpalladium(Fe-Pd) benzene monosolvate

The title binuclear μ-pyridyl­vinyl­idene FePd complex (FePd1) was obtained from Cp(CO)₂FeI and 2-ethynyl­pyridine in diisorpopyl­amine in the presence of PdCl₂

The reaction of Cp(CO)₂FeI with 2-ethynyl­pyridine under Sonogashira conditions [5% PdCl₂(PPh₃)₂, 10% CuI, THF–NEt₃ (2:1)] afforded the title binuclear μ-pyridyl­vinyl­idene FePd complex (FePd1) as a benzene solvate, [FePd(C₅H₅)(C₇H₅N)I(CO)₂]·C₆H₆, in a very low yield rather than the expected iron o-pyridyl­ethynyl complex Cp(CO)₂Fe—C≡C-(2-C₅H₄N). The Fe and Pd atoms in FePd1 are bridged by carbonyl and pyridyl­vinyl­idene ligands, the pyridyl N atom being bonded to the palladium atom. The use of equimolar amounts of PdCl₂ increases the yield of FePd1 to 12%. The reaction pathway leading to FePd1 is proposed.

The half-sandwich 18- and 16-electron arene ruthenium iminophosphonamide complexes

Novel arene ruthenium iminophosphonamides are electron-rich complexes due to a strong σ,π-donor zwitterionic ligand.

Synthesis Of New Cyclopentadienyl-, Indenyl- And Fluorenylphosphanes By The Reaction Of Carbanions Of The Cyclopentadienyl Type With Alkyl(Aryl)Chloro-N,N-Dialkylaminophosphanes

A number of alkyl(aryl)chloro-N,N-dialkylaminophosphanes RP(Cl)NR1R2 (1a-o ) were synthesized starting from alkyl(aryl)dichlorophosphanes RPCl2 and amines by a convenient procedure with nearly quantitative yields. The reactivity of alkyl(aryl)-N,N-dialkylamino(halogeno) phosphanes RP(Hal)NR1R2 (Hal = Cl, I) with cyclopentadienyl, bis(cyclopentadienyl), indenyl, bis(indenyl) and fluorenyl carbanions has been investigated. The new aminocyclopentadienylphosphanes R„Cp(R)PNR1R2 2a-f and 3a-c (R„Cp = Ind, Flu, Cp2CMe2, Ind2CEt2, Ind2(CH2)2) were characterized by spectroscopic techniques and elemental analyses. Flu(t-Bu)PN(H)t-Bu (2f) was characterized by X-ray diffraction analysis