Phosphorylation of C-alkenylsubstituted pyrazoles with phosphorus pentachloride

Ларина, Л. И.; Rudyakova, E. V.; Savosik, V. A.; Levkovskaya, G. G.; Rozinov, V. G.; Dmitrichenko, M. Yu.

doi:10.1134/s1070363209060358

Cited by 7 publications

(9 citation statements)

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“…The conditions of synthesis and physicochemical parameters of compounds I-IV were reported in [5,6].…”

Section: Methodsmentioning

confidence: 99%

“…On the other hand, the presence in the heterorings of I and II of pyridine-type nitrogen atoms possessing enhanced nucleophilicity suggests that attack by phosphorus pentachloride can be directed at the heteroring with formation of the corresponding donor-acceptor molecular complexes III and IV [5,6] (Scheme 1) rather than at the side-chain double bond. The 31 P NMR spectra of III and IV contained a singlet in the region δ P -258 to -296 ppm, which is typical of six-coordinate phosphorus atom.…”

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confidence: 97%

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Quantum-chemical calculations of NMR chemical shifts of organic molecules: IV. Effect of intermolecular coordination on 31P NMR shielding constants and chemical shifts of molecular complexes of phosphorus pentachloride with azoles

et al. 2011

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Intermolecular coordination effects on the 31 P NMR spectra of molecular complexes of N-vinylimidazole and 1-allyl-3,5-dimethylpyrazole with phosphorus pentachloride were studied by theoretical and experimental methods. The formation of intermolecular dative N→P bond was shown to be accompanied by upfield shift of the phosphorus resonance signal by more than 200 ppm. Appreciable contribution of relativistic effects to 31 P NMR chemical shifts was revealed; the spin-orbital contribution to 31 P shielding constant was estimated at >210 ppm. Consideration of solvent effect was found to be crucial while studying steric structure of molecular complexes of azoles with phosphorus pentachloride and intermolecular coordination effects on 31 P NMR chemical shifts. * For communication III, see [1].We previously studied by theoretical methods the effect of intramolecular coordination on 31 P NMR shielding constants (chemical shifts) of [2-(1H-pyrazol-1-yl)ethenyl]phosphonium hexachlorophosphate(V) and 1,1,1,1-tetrachloro-1H-1λ 5 -pyrazolo[1,2-a][1,2,3]-diazaphosphol-8-ium-1-ide [1]. While developing our studies on theoretical calculations of 31 P chemical shifts [1][2][3], in the present work we examined molecular complexes of phosphorus pentachloride with some azoles, N-vinylimidazole (I) and 1-allyl-3,5-dimethylpyrazole (II). In keeping with the results of our experimental [4] and theoretical studies [1], the phosphorus atom in chlorophosphonium group is capable of forming a dative bond with pyridine-type nitrogen atom (i.e., sp 2 -nitrogen atom possessing an unshared electron pair). As a result, the coordination number of phosphorus increases to 5 or 6, and its resonance signal in the 31 P NMR spectrum is displaced upfield; therefore, 31 P NMR spectroscopy can be used to analyze structure of such intramolecular complexes.On the other hand, the presence in the heterorings of I and II of pyridine-type nitrogen atoms possessing enhanced nucleophilicity suggests that attack by phosphorus pentachloride can be directed at the heteroring with formation of the corresponding donor-acceptor molecular complexes III and IV [5, 6] (Scheme 1) rather than at the side-chain double bond. The 31 P NMR spectra of III and IV contained a singlet in the region δ P -258 to -296 ppm, which is typical of six-coordinate phosphorus atom. With a view to estimate the effect of intermolecular coordination on the 31 P shielding constants (chemical shifts) and prove the formation of dative bond in molecular complexes III and IV, we performed quantum-chemical calculations of 31 P NMR chemical shifts for the gas phase and with account taken of solvent effect (see table).The phosphorus shielding constants were calculated at the GIAO-B3LYP/DZP level of theory with account

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“…The conditions of synthesis and physicochemical parameters of compounds I-IV were reported in [5,6].…”

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 97%

Quantum-chemical calculations of NMR chemical shifts of organic molecules: IV. Effect of intermolecular coordination on 31P NMR shielding constants and chemical shifts of molecular complexes of phosphorus pentachloride with azoles

et al. 2011

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“…2‐(1‐Pytazolyl)ethenyltrichlorophosphonium hexachlorophosphorate ( 1 ) and 2‐(1‐pyrozolyl)ethenyltetrachlorophosphonium ( 2 ) were synthesised via the phosphorylation of N ‐vinylpyrazole with phosphorous pentachloride, 6 whereas intermolecular complexes of N ‐vinylimidazole and 1‐allyl‐3,5‐dimethilpyrazole with phosphorous pentachloride, accordingly 3 and 4 , were obtained as described elsewhere . All products under study obtained in this way (compounds 1–4 ) were identified according to the published NMR data …”

Section: Methodsmentioning

confidence: 99%

The effects of intramolecular and intermolecular coordination on ³¹P nuclear shielding: phosphorylated azoles

Chernyshev

Ларина²,

Chirkina³

et al. 2012

Magnetic Reson in Chemistry

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The effects of intramolecular and intermolecular coordination on (31)P nuclear shielding have been investigated in the series of tetracoordinated, pentacoordinated and hexacoordinated N-vinylpyrazoles and intermolecular complexes of N-vinylimidazole and 1-allyl-3,5-dimethylpyrazole with phosphorous pentachloride both experimentally and theoretically. It was shown that either intramolecular or intermolecular coordination involving phosphorous results in a dramatic (31)P nuclear shielding amounting to approximately 150 ppm on changing the phosphorous coordination number by one. A major importance of solvent effects on (31)P nuclear shielding of intramolecular and intermolecular complexes involving N → P coordination bond has been demonstrated. It was found that the zeroth-order regular approximation-gauge-including atomic orbital-B1PW91/DZP method was sufficiently accurate for the calculation of (31)P NMR chemical shifts, provided relativistic corrections are taken into account, the latter being of crucial importance in the description of (31)P nuclear shielding.

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“…1 Н, 13 С, and 31 Р NMR data of complexes 28-31 are shown in Table 8. 1-allyl-3,5-dimethylpyrazole [32] and the corresponding 1-propyl and 1-isopropyl derivatives interact with phosphorus pentachloride exclusively with the participation of the pyridine nitrogen atom of heterocycle. The presence of a pyridine nitrogen atom with increased nucleophilicity in the azole ring directs the attack of phosphorus pentachloride into the heterocycle to form the donor-acceptor complexes 32, 32-1 and 32-2 (Scheme 9).…”

Section: The Structural Features Of Molecular Complexes Of Vinylazole...mentioning

confidence: 99%

“…The stereochemical structure of phosphorus-containing azoles obtained by the action of phosphorus pentachloride on vinylazoles and related compounds was studied by multinuclear 1 H, 13 C, 15 N, 31 P, and two-dimensional (2D) NMR spectroscopy [22,[30][31][32][33][34].…”

Section: Introductionmentioning

confidence: 99%

Organophosphorus Azoles Incorporating a Tetra-, Penta-, and Hexacoordinated Phosphorus Atom: NMR Spectroscopy and Quantum Chemistry

Ларина

2023

Molecules

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The review presents extensive data (from the author’s work and the literature) on the stereochemical structure of functionalized organophosphorus azoles (pyrroles, pyrazoles, imidazoles and benzazoles) and related compounds, using multinuclear 1Н, 13С, 31Р NMR spectroscopy and quantum chemistry. 31P NMR spectroscopy, combined with high-level quantum-chemical calculations, is the most convenient and reliable approach to studying tetra-, penta-, and hexacoordinated phosphorus atoms of phosphorylated N-vinylazoles and evaluating their Z/E isomerization.

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Phosphorylation of C-alkenylsubstituted pyrazoles with phosphorus pentachloride

Cited by 7 publications

References 1 publication

Quantum-chemical calculations of NMR chemical shifts of organic molecules: IV. Effect of intermolecular coordination on 31P NMR shielding constants and chemical shifts of molecular complexes of phosphorus pentachloride with azoles

Quantum-chemical calculations of NMR chemical shifts of organic molecules: IV. Effect of intermolecular coordination on 31P NMR shielding constants and chemical shifts of molecular complexes of phosphorus pentachloride with azoles

The effects of intramolecular and intermolecular coordination on ³¹P nuclear shielding: phosphorylated azoles

Organophosphorus Azoles Incorporating a Tetra-, Penta-, and Hexacoordinated Phosphorus Atom: NMR Spectroscopy and Quantum Chemistry

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Phosphorylation of C-alkenylsubstituted pyrazoles with phosphorus pentachloride

Cited by 7 publications

References 1 publication

Quantum-chemical calculations of NMR chemical shifts of organic molecules: IV. Effect of intermolecular coordination on 31P NMR shielding constants and chemical shifts of molecular complexes of phosphorus pentachloride with azoles

Quantum-chemical calculations of NMR chemical shifts of organic molecules: IV. Effect of intermolecular coordination on 31P NMR shielding constants and chemical shifts of molecular complexes of phosphorus pentachloride with azoles

The effects of intramolecular and intermolecular coordination on 31P nuclear shielding: phosphorylated azoles

Organophosphorus Azoles Incorporating a Tetra-, Penta-, and Hexacoordinated Phosphorus Atom: NMR Spectroscopy and Quantum Chemistry

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The effects of intramolecular and intermolecular coordination on ³¹P nuclear shielding: phosphorylated azoles