Use of Lawesson's reagent in organic syntheses.

The carbon-13 chemical shifts and coupling constants of 1168 pyrazoles are reported, some of them in several solvents. These data are briefly discussed on the basis of statistical treatment and qualitative comparisons.

13C NMR of pyrazoles

Some new phosphoramidates were synthesized and characterized by 1H, 13C, 31P NMR, IR spectroscopy and elemental analysis. The structures of CF3C(O)N(H)P(O)[N(CH3)(CH2C6H5)]2 (1) and 4-NO2-C6H4N(H)P(O)[4-CH3-NC5H9]2 (6) were confirmed by X-ray single crystal determination. Compound 1 forms a centrosymmetric dimer and compound 6 forms a polymeric zigzag chain, both via -N-H…O=P- intermolecular hydrogen bonds. Also, weak C-H…F and C-H…O hydrogen bonds were observed in compounds 1 and 6, respectively. 13C NMR spectra were used for study of 2J(P,C) and 3J(P,C) coupling constants that were showed in the molecules containing N(C2H5)2 and N(C2H5)(CH2C6H5) moieties, 2J(P,C)>3J(P,C). A contrast result was obtained for the compounds involving a five-membered ring aliphatic amine group, NC4H8. 2J(P,C) for N(C2H5)2 moiety and in NC4H8 are nearly the same, but 3J(P, C) values are larger than those in molecules with a pyrrolidinyl ring. This comparison was done for compounds with six and seven-membered ring amine groups. In compounds with formula XP(O)[N(CH2R)(CH2C6H5)]2, 2J(P,CH2)benzylic>2J(P,CH2)aliphatic, in an agreement with our previous study.

2J(P,C) and 3J(P,C) Coupling Constants in Some New Phosphoramidates. Crystal Structures of CF3C(O)N(H)P(O)[N(CH3)(CH2C6H5)]2 and 4-NO2-C6H4N(H)P(O)[4-CH3-NC5H9]2

https://profdoc.um.ac.ir/articles/a/1011574.pdf

The effect of various substituents on the structural parameters of the P(O)[N(CH3)(CH2C6H5)]2 moiety. Syntheses and spectroscopic characterization of some new phosphoramidates, crystal structures of P(O)(X)[N(CH3)(CH2C6H5)]2, X = C6H5C(O)NH, Cl and CCl3C(O)NH

The effect of various substituents on the structural parameters of

4-Phosphopyrazoles are prepared with good yield by cyclisation of hydrazone phosphorus compounds and ethylortho formiate. The effects of substitution are investigated on the 13C chemical shifts of pyrazole ring. The magnitude of the coupling constant 1 J pc is in good agreement with the hybridization of the phosphorus atom.

Phospho-4-pyrazoles. synthese et etude spectrographique rmn 1h, 31p et 13c

δ5-3-dimethylamino-3-oxo-1,2,3-diazaphospholines are prepared by cyclisation of bis(dimethylami-no)phosphinallene oxides containing two electrophilic sites in position 1.3 (phosphorus atom and medium carbon allenic) with hydrazine derivatives. Mechanistic explanations of these results have been described by NMR. The IR and the 31P, 13C, 1H chemical shifts of diazaphosphollines oxides are commented.

Oxydes de diazaphospholines-1,2,3: synthese et etude spectrographique ir et de rmn 1h, 31p, 13c

β-Phosphonylhydrazone 1 are considered as reagents in heterocyclic synthesis (Pyrazoles phosphonated, Diazaphospholines oxides). In the present work, we study the reaction of hydrazones β-disubtituted phosphine oxide 1 with Lawesson reagent (L R) to lead to the 3-thioxo-1,2,3-diazaphospholines derivatives 2 . The structure of products 2 is confirmed by NMR and IR spectroscopy.

ACTION DU REACTIF DE LA WESSON SUR LES HYDRAZONES β-PHOSPHONATEES: SYNTHESE DE Δ5-5-(METHYLENE-PHOSPHINEOXYDE)-3-THIOXO-1,2,3-DIAZAPHOSPHOLINES

Carbon-13 chemical shifts and J(POC) and J(PNC) values have been determined for a series of substituted 2-oxo- and 2-thio-2-phenoxy-1,3,2-diazaphosphorinanes and related P(IV) compounds. 31P and 1H NMR were used in conjunction with 13C NMR spectra to establish some aspects of the stereochemistry of these compounds. 3J(PNCC) and 3J(POCC) seem to be more sensitive to the stereostructure than the 13C chemical shifts.

Carbon-13 chemical shift assignment of some organophosphorus compounds. IV—2-oxo- and 2-thio-2-phenoxy-1,3,2-diazaphosphorinanes and related P(IV) compounds

Carbon-13 chemical shifts and the POC, POCC, PNC and PNCC coupling constants of 18 compounds containing the amine moiety, and with the general formula Y2P(X)NHR [Y=C2H5O, C6H5O, CH2O, Y2=1,2-dioxybenzene; X = O or S; R = H, CH3, C2H5, PhCH2CH2, (CH3)2CH, C(CH3)3, C6H11, C6H5, C6H5NH] have been determined. The Y2P(X) group shows a sterically induced effect on the amine moiety; the 13C chemical shift of the Y group is, however, almost unaffected on replacing P(O) by a P(S) group.

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Papers

Phospho-4-pyrazoles. synthese et etude spectrographique rmn 1h, 31p et 13c

Oxydes de diazaphospholines-1,2,3: synthese et etude spectrographique ir et de rmn 1h, 31p, 13c

ACTION DU REACTIF DE LA WESSON SUR LES HYDRAZONES β-PHOSPHONATEES: SYNTHESE DE Δ5-5-(METHYLENE-PHOSPHINEOXYDE)-3-THIOXO-1,2,3-DIAZAPHOSPHOLINES

Carbon-13 chemical shift assignment of some organophosphorus compounds. IV—2-oxo- and 2-thio-2-phenoxy-1,3,2-diazaphosphorinanes and related P(IV) compounds

Carbon-13 chemical shift assignment of some organophosphorus compounds: 1—Dialkyl and diaryl (alkylamido)phosphates with general formula Y2P(X)NHR