Direct reaction of photogenerated diarylcarbenes at square-planar rhodium(<scp>i</scp>)

Duckett, Simon B.; Gálvez-López, María-Dolores; Perutz, Robin N.; Schott, Danièle

doi:10.1039/b407735k

Cited by 10 publications

(6 citation statements)

References 39 publications

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“…When Et 3 SiH and (PPh 3 ) 3 RhCl were combined in a 1:1 or 2:1 ratio, a new 1 H NMR resonance consistent with a Rh−H species was observed at −7.9 ppm. Esteruelas et al observed the same result and assigned the resonance to (PPh 3 ) 3 RhH. , In our system, when excess Et 3 SiH (>10 equiv) is allowed to react with (PPh 3 ) 3 RhCl, the only rhodium hydride complex observed initially is (PPh 3 ) 2 RhH(Cl)SiEt 3 , identified by the upfield hydride resonance (δ −14.7, J Rh−H = 22 Hz) in the 1 H{ 31 P} NMR spectrum and its 31 P{ 1 H} resonance (δ 39.7, d, J Rh−P = 128 Hz) . With time, the (PPh 3 ) 2 RhH(Cl)SiEt 3 1 H resonance at −14.7 ppm disappears, and the (PPh 3 ) 3 RhH resonance, −7.9 ppm, appears .…”

Section: Resultssupporting

confidence: 81%

Phosphinorhodium-Catalyzed Dehalogenation of Chlorinated and Fluorinated Ethylenes: Distinct Mechanisms with Triethylsilane and Dihydrogen

2009

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Catalytic dehalogenation of chlorinated and fluorinated ethylenes by (PR 3 ) 3 RhCl complexes is described. The C-Cl and C-F bonds are activated by the catalyst in the presence of triethylsilane (Et 3 SiH) or dihydrogen (H 2 ). Spectroscopic studies, in addition to substrate preference, indicate that rhodium hydride species are important intermediates. Kinetic parameters and product distribution for dehalogenation reactions were determined using NMR spectroscopy. Evidence for sequential chlorine removal was obtained, and the rates of dehalogenation were found to increase with decreasing halogen content. It was also shown that this catalytic system has a preference for sp 2over sp 3 -hybridized carbon-halogen bonds. Dechlorination using (PPh 3 ) 3 RhCl and either H 2 or Et 3 SiH supports an insertion/β-chloride elimination mechanism; however, the two systems display distinct differences. On the basis of these differences, the dominant pathway for Et 3 SiH is proposed to involve rhodium(I), while the H 2 system is proposed to primarily involve rhodium(III). This is supported with isotopic labeling studies using D 2 , Et 3 SiD, and (PPh 3 ) 3 RhD, which yield different stereochemistry of dechlorinated products. With D 2 , only products consistent with syn-β-chloride elimination were observed, while with Et 3 SiD and (PPh 3 ) 3 RhD both syn-and anti-β-chloride elimination products were observed. In addition, NMR spectroscopic evidence of different hydride intermediates in the H 2 and Et 3 SiH systems was obtained. Different pathways for dehalogenation with Et 3 SiH and H 2 is further supported by the observation of 1,2-addition (hydrogenation) products using H 2 and the lack of 1,2-addition (hydrosilylation) products using Et 3 SiH.

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Section: Resultssupporting

confidence: 81%

Phosphinorhodium-Catalyzed Dehalogenation of Chlorinated and Fluorinated Ethylenes: Distinct Mechanisms with Triethylsilane and Dihydrogen

2009

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“…CDCl 3 and C 6 D 12 were dried over molecular sieves. KC 8 , 76 (p-tol) 2 CN 2 , 77 and [{(TMS)CH 2 } 2 Pd-(COD)] 50 were prepared according to literature procedures. All other chemicals were commercially available and were used as received.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

An Adaptable Chelating Diphosphine Ligand for the Stabilization of Palladium and Platinum Carbenes

Barrett

Iluc

2017

Organometallics

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Group 10 metal carbenes are proposed in catalytic transformations; however, their isolation remains difficult without the presence of a heteroatom donor. The adaptable cis and trans coordinating ligand PterP (1,2-bis(2-(diisopropylphosphino)phenyl)benzene) is key in stabilizing two-coordinate palladium and platinum(0) precursors. Reacting these precursors with di-p-tolyldiazomethane ((p-tol)2CN2) leads to the formation of the unprecedented trigonal-planar diarylcarbenes [(PterP)MC(p-tol)2] (M = Pd, Pt), upon transformation of the trans coordinating ligand into a wide-bite, cis-coordinating ligand. Both palladium and platinum diarylcarbenes were characterized by multinuclear NMR spectroscopy. The unusual stability of the platinum analogue allowed its characterization via X-ray crystallography. Furthermore, the reactivity of the palladium and platinum diarylcarbenes with Ph2SiH2 and CH3I was investigated.

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“…This let us assume that treatment of SiX 2 (NHC) and SiRX(NHC) with diazoalkanes might be a viable route to unprecedented silazines, the silicon analogues of phosphazines. For this purpose, the reaction of SiI 2 (Idipp) ( 1 ) with bis( p ‐tolyl)diazomethane ( p ‐Tol) 2 CN 2 ( p ‐Tol = C 6 H 4 ‐4‐Me) was studied.…”

Section: Resultsmentioning

confidence: 99%

NHC‐stabilized Silicon(II) Halides: Reactivity Studies with Diazoalkanes and Azides

Arz

Hoffmann

Schnakenburg

et al. 2016

Zeitschrift anorg allge chemie

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Direct reaction of photogenerated diarylcarbenes at square-planar rhodium(i)

Cited by 10 publications

References 39 publications

Phosphinorhodium-Catalyzed Dehalogenation of Chlorinated and Fluorinated Ethylenes: Distinct Mechanisms with Triethylsilane and Dihydrogen

Phosphinorhodium-Catalyzed Dehalogenation of Chlorinated and Fluorinated Ethylenes: Distinct Mechanisms with Triethylsilane and Dihydrogen

An Adaptable Chelating Diphosphine Ligand for the Stabilization of Palladium and Platinum Carbenes

NHC‐stabilized Silicon(II) Halides: Reactivity Studies with Diazoalkanes and Azides

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