Reactions of sodium 3,4,5-triphenyl-1,2-diphosphacyclopentadienide with alkyl halides and silicon and tin chlorides

Milyukov, V. A.; Bezkishko, Ilya A.; Zagidullin, Almaz; Sinyashin, Оleg G.; Hey‐Hawkins, Evamarie

doi:10.1007/s11172-010-0226-9

Cited by 22 publications

(12 citation statements)

References 13 publications

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“…The 31 P{ 1 H} NMR spectra of 1 in the temperature range of –80 to +25 °C show only two doublets at δ = 74 and 195 ppm, which are characteristic of tri‐ and dicoordinate phosphorus atoms, respectively, with a large 1 J P,P coupling constant of about 453 Hz. Compared with 3,4,5‐triphenyl‐1‐isopropyl‐1,2‐diphosphole ( δ P = 63 and 208 ppm, 1 J P,P = 421 Hz),14 1 exhibits a smaller chemical shift difference for the tri‐ and dicoordinate phosphorus atoms and a larger 1 J P,P coupling constant, which indicates significant delocalization of the lone pair of electrons of the tricoordinate phosphorus atom into the heterocyclic system 15. Compound 1 crystallizes in the non‐centrosymmetric P 2 1 space group with a Flack parameter of –0.04(6).…”

Section: Resultsmentioning

confidence: 98%

Diastereoselective [4+2] Cycloaddition Reaction of 1‐Neomenthyl‐1,2‐diphosphole: Facile Synthesis of P‐Chiral Cage Phosphines

et al. 2015

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3,4,5‐Triphenyl‐1‐(+)‐neomenthyl‐1,2‐diphosphole was obtained by alkylation of sodium 3,4,5‐triphenyl‐1,2‐diphosphacyclopentadienide with (–)‐menthyl tosylate. High delocalization within the planar heterocycle of the diphosphole is indicative of low aromaticity. Thus, the [4+2] cycloaddition reaction of this compound with maleic anhydride proceeded under mild conditions with high diastereoselectivity (up to 88 % de) and resulted in the corresponding enantiopure 1,7‐diphosphanorbornadiene as an individual enantiomer. The observed high diastereoselectivity may be explained by thermodynamic control of the reaction.

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Section: Resultsmentioning

confidence: 98%

Diastereoselective [4+2] Cycloaddition Reaction of 1‐Neomenthyl‐1,2‐diphosphole: Facile Synthesis of P‐Chiral Cage Phosphines

et al. 2015

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“…The nickel ethylene complex [Ni(C 2 H 4 )(dtbpe)] was prepared according to the literature . 1-Alkyl-1,2-diphospholes 1 – 4 were prepared by alkylation of the corresponding 3,4,5-triaryl-1,2-diphosphacyclopentadienides (aryl = Ph, p -ClC 6 H 4 , p -FC 6 H 4 ). Syntheses of complexes 5 – 8 (Scheme ) were carried out in situ directly in an NMR tube because of their extreme sensitivity to oxygen and moisture.…”

Section: Resultsmentioning

confidence: 99%

Structural Diversity and Dynamics of Nickel Complexes with Ambidentate Phosphorus Heterocycles

et al. 2018

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The reaction of [Ni(C 2 H 4 )(dtbpe)] with 1-alkyl-1,2-diphospholes afforded [Ni(1-alkyl-1,2-diphosphole)(dtbpe)] complexes. Both DNMR experimental and DFT calculation results have shown that in solution these complexes are in an equilibrium of two P−P side-on η 2 -coordinated 1-alkyl-1,2-diphosphole isomers. In one form, unusual η 2 bonding occurred at a P 2 −P 1 side, presumably at the expense of a vicinal P 2 −C 1 π bond, and it could be characterized as a phosphametallacycle with the formal oxidation state of Ni(II). In the second isomer with the Ni(0) state, Ni bonds to the ligand through two σ interactions with phosphorus lone pairs. The P 2 chemical shift, being heavily dependent on structure, can be used to monitor these isomer populations.

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“…The structures of the obtained compounds, 1a–e , were unambiguously confirmed by 31 Р, 1 Н and 13 С NMR spectroscopy. The 31 P NMR spectra of 1a–e ( Table 1 ) showed two doublets in the range of 30–60 and 210–225 ppm, corresponding to three- and two-coordinated phosphorus atoms, respectively, with a large coupling constant 1 J PP ≈ 365–410 Hz, which is typical for 1-alkyl-1,2-diphospholes [ 15 ].…”

Section: Resultsmentioning

confidence: 99%

Enhancing the reactivity of 1,2-diphospholes in cycloaddition reactions

Zagidullin¹,

Miluykov²,

Oshchepkova³

et al. 2015

Beilstein J. Org. Chem.

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SummaryTwo different approaches have been employed to enhance the reactivity of 1-alkyl-1,2-diphospholes – the introduction of electron-withdrawing groups either at the phosphorus atoms or in the para-position of the arene ring. The alkylation of sodium 1,2-diphospha-3,4,5-triphenylcyclopentadienide with alkyl halides Hal-CH2-R (R = CN, COOEt, OMe, CH2OEt) results in corresponding 1-alkyl-3,4,5-triphenyl-1,2-diphospholes (alkyl = CH2CN (1a), CH2COOEt (1b), CH2OMe (1c), and (CH2)2OEt (1d)), which spontaneously undergo the intermolecular [4 + 2] cycloaddition reactions at room temperature to form the mixture of the cycloadducts, 2a–c, respectively. However the alkylation of sodium 1,2-diphospha-3,4,5-tri(p-fluorophenyl)cyclopentadienide with ethyl iodide leads to stable 1-ethyl-3,4,5-tris(p-fluorophenyl)-1,2-diphosphole (1e), which forms the [4 + 2] cycloadduct 2,3,4,4a,5,6-hexa(p-fluorophenyl)-1-ethyl-1,7,7a-triphospha-4,7-(ethylphosphinidene)indene (2e) only upon heating up to 60 °C. With further heating to 120 °C with N-phenylmaleimide, the cycloadducts 2a–c and 2e undergo the retro-Diels–Alder reaction and form only one product of the [4 + 2] cycloaddition reaction 3a–с, 3e with good yields up to 65%.

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Reactions of sodium 3,4,5-triphenyl-1,2-diphosphacyclopentadienide with alkyl halides and silicon and tin chlorides

Cited by 22 publications

References 13 publications

Diastereoselective [4+2] Cycloaddition Reaction of 1‐Neomenthyl‐1,2‐diphosphole: Facile Synthesis of P‐Chiral Cage Phosphines

Diastereoselective [4+2] Cycloaddition Reaction of 1‐Neomenthyl‐1,2‐diphosphole: Facile Synthesis of P‐Chiral Cage Phosphines

Structural Diversity and Dynamics of Nickel Complexes with Ambidentate Phosphorus Heterocycles

Enhancing the reactivity of 1,2-diphospholes in cycloaddition reactions

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