Phosphorus-31 and carbon-13 solid-state NMR of tertiary phosphine-palladium complexes bound to silica

Komoroski, Richard A.; Magistro, Angelo J.; Nicholas, Paul P.

doi:10.1021/ic00242a019

Cited by 58 publications

(43 citation statements)

References 5 publications

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“…It features as et of relativelym inor spinnings idebands, spaced by the magic-angle spinning (MAS)f requency.T he centerbandr evealed three components, markedb yt he dotted lines in the zoomed spectrumi nF igure 4b.T he two main peaks around2 8a nd 21 ppm stem from complex 3 and are tentatively assigned to each of the Pa toms showni nS cheme1.T he widths of the relatively broad 31 PNMR peaks are primarily dictated by structural disorder,a nd unresolved scalar couplings to 103 Rh. Besides am inor 31 PNMR peak at about 42 ppm, attributed to an oxidation product impurity (such NMR signals appear typically above 40 ppm [38,39] ), the absence of additional resonances reflects ap ure sample of complex 3.T he NMR spectrum reveals no traces of residual MeO-TPPMS (1b), which were observed to generate as harp 31 PNMR peak at À10 ppm (data not shown).…”

Section: Pn Mrmentioning

confidence: 93%

Single Site Supported Cationic Rhodium(I) Complexes for the Selective Redox Isomerization of Allylic Alcohols

et al. 2012

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The isomerization of allylic alcohols to carbonyl compounds by a heterogeneous rhodium complex is reported. Different silica material supports and catalyst/ligand systems were evaluated. The most efficient catalyst in terms of catalytic activity and stability was found to be a cationic rhodium(I) complex with sulfonated phosphine ligands anchored on a mesoporous aluminosilica AlSBA‐15. The heterogeneous complex catalyzed the isomerization of a variety of allylic alcohols in excellent yields with very low catalyst loadings (0.5 mol %). The catalyst could be recycled without significant loss of activity or selectivity. The optimized catalyst was characterized by N2 sorption, powder X‐ray diffraction, transmission electron microscopy, as well as solution and solid‐state nuclear magnetic resonance, and Fourier Transform infrared spectroscopies.

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Section: Pn Mrmentioning

confidence: 93%

Single Site Supported Cationic Rhodium(I) Complexes for the Selective Redox Isomerization of Allylic Alcohols

et al. 2012

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“…[53] The PdCl 2 {PPh 2 -(CH 2 ) 2 -SiCH 3 (OCH 2 CH 3 ) 2 } 2 was synthesized by reacting 2 equivalents of PPh 2 -(CH 2 ) 2 -SiCH 3 (OCH 2 CH 3 ) 2 with bis(benzonitrile)palladium dichloride at room temperature in dichloromethane by adapting a procedure reported elsewhere. [54] Preparation of [Pd(NH 3 ) 4 ] 2 þ /NaY [41] A 0. [42] Mesoporous SBA-15 type silica was used as support and was prepared by the acid-catalysed, non-ionic assembly pathway described by Margolese et al [55] The structure directing agent (Pluronic 123) was removed by calcination under air at 500 8C and the surfactant-free mesoporous silica was rigorously dried under a flow of nitrogen at 200 8C prior to the grafting reaction.…”

Section: Catalyst Preparationmentioning

confidence: 99%

Heterogeneous Palladium Catalysts Applied to the Synthesis of 2- and 2,3-Functionalised Indoles

Djakovitch¹,

Dufaud²,

Zaidi³

2006

Adv. Synth. Catal.

115

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Abstract:Heterogeneous palladium catalysts ([Pd(NH 3 ) 4 ] 2 þ /NaY and [Pd]/SBA-15) were applied to the synthesis of 2-functionalised indoles, giving generally high conversions and selectivities ( > 89% yield) using only 1 mol % [Pd]-catalyst under standard reaction conditions (polar solvent, 80 8C). For the synthesis of 2,3-functionalised indoles by crosscoupling arylation, the [Pd]/SBA-15 catalyst was found to be particularly interesting, producing the expected compound with ¼ 35% yield after 12 days of reaction, which is comparable to the homogeneous catalyst, Pd(OAc) 2 ( ¼ 48% yield). In the course of the study, the dual reactivity of the indole nucleus was demonstrated: aryl bromides gave clean C À C coupling while aryl iodides led to a clean C À N coupling.

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“…Si, and 13 C CP/MAS NMR spectra of recovered 4(2)Pd after the catalysis as well as fresh 4(2)Pd. The peak corresponding to phosphine coordinated on palladium atom (P-Pd) was observed around 20 ppm 23) in the 31 P CP/MAS spectrum of 4(2) Pd before and after catalysis. No significant changes in the 31 P, 29 Si, and 13 C CP/MAS NMR peaks were observed before and after the catalysis, except for increased phosphine oxide.…”

Section: Active Species Of the Palladium Catalystmentioning

confidence: 99%

Application of Tripodal Linker Units to Immobilized Diphenylphosphine Palladium Complex Catalysts for Suzuki-Miyaura Coupling Reactions of Aryl Bromide: Effect of Immobilization Method of Phosphine Ligand on Catalytic Performance

訓久

孝行²,

俊也

et al. 2016

J. Jpn. Petrol. Inst.

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A tripodal linker unit that tightly binds to a silica surface via three independent Si _ O _ Si bonds was applied to immobilize diphenylphosphino-palladium complex catalysts onto ordered mesoporous silica. The diphenylphosphino-functionalized silica materials were prepared by: (i) grafting the bromine-substituted tripodal linker unit onto mesoporous silica and a subsequent treatment with potassium diphenylphosphide (the "bottom-up" method), (ii) directly grafting pre-synthesized tripodal diphenylphosphino ligands onto silica (the "top-down" method). The catalytic properties were evaluated in the Suzuki-Miyaura coupling reaction of aryl bromides. The tripodally immobilized catalyst prepared via the "bottom-up" method showed lower leaching levels of palladium and phosphorus compared to catalyst prepared via the "top-down" method.

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Phosphorus-31 and carbon-13 solid-state NMR of tertiary phosphine-palladium complexes bound to silica

Cited by 58 publications

References 5 publications

Single Site Supported Cationic Rhodium(I) Complexes for the Selective Redox Isomerization of Allylic Alcohols

Single Site Supported Cationic Rhodium(I) Complexes for the Selective Redox Isomerization of Allylic Alcohols

Heterogeneous Palladium Catalysts Applied to the Synthesis of 2- and 2,3-Functionalised Indoles

Application of Tripodal Linker Units to Immobilized Diphenylphosphine Palladium Complex Catalysts for Suzuki-Miyaura Coupling Reactions of Aryl Bromide: Effect of Immobilization Method of Phosphine Ligand on Catalytic Performance

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