Reactions of oxalyl fluoride with electrophiles

The reactions of oxalyl fluoride with electrophiles in the presence of alkali metal fluoride were carried out. In the reaction with CF₃CH₂OTf (Tf=CF₃SO₂) or CH₃CH₂OTf, the synthesis of di-ether (ROCF₂CF₂OR) and mono-ether (ROCF₂COF) was achieved. The difference of the reactivities between these two compounds was discussed from the result of DFT calculations.     

Chemistry of oxalyl derivatives of methyl ketones

It was established by IR, UV, and PMR spectroscopy that 2-phenacylidenebenzo-1,4-thiazin-3-ones are formed in the reaction of o-aminothiophenol with aroylpyruvic acids or 5-arylfuran-2,3-diones. 2-Carbomethoxy-2-phenacyl-1,3-benzothiazolines were isolated in the reaction of o-aminothiophenol with aroylpyruvic acid esters.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 755–757, June, 1977.     

The reactions of bisamides with oxalyl chloride

Alkylidenebisamides and alkylidenebiscarbamates were found to react with oxalyl chloride to give oxazolidinediones ( 2 ), a diazepinedione ( 3 ) or fragmentation products depending on the nature of the substituents (R' in formula 1 ).     

The reaction of carboxamidines with oxalyl chloride

The action of oxalyl chloride on amidines has given imidazoline-4,5-dione hydrochlorides. The reactions of the imidazoline-4,5-diones and their hydrochlorides with water, alcohols, and amines have been studied. In these reactions the imidazoline ring readily opens with the formation of derivatives of oxaminic acid.For Communication II, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 6, pp. 814–818, June, 1970.     

Observation of dihalide elimination upon electron attachment to oxalyl chloride and oxalyl bromide, 300-550 K

Rate coefficients have been measured for electron attachment to oxalyl chloride [ClC(O)C(O)Cl] and oxalyl bromide [BrC(O)C(O)Br] in He gas at 133 Pa pressure over the temperature range of 300-550 K. With oxalyl chloride, the major ion product of attachment is Cl2(-) at all temperatures (66% at 300 K); its importance increases slightly as temperature increases. Two other product ions formed are Cl- (18% at 300 K) and the phosgene anion CCl2O- (16% at 300 K) and appear to arise from a common mechanism. With oxalyl bromide, the Br2(-) channel represents almost half of the ion product of attachment, independent of temperature. Br- accounts for the remainder. For oxalyl chloride, the attachment rate coefficient is small [(1.8 +/- 0.5) x 10(-8) cm3 s(-1) at 300 K], and increases with temperature. The attachment rate coefficient for oxalyl bromide [(1.3 +/- 0.4) x 10(-7) cm3 s(-1) at 300 K] is nearly collisional and increases only slightly with temperature. Stable parent anions C2Cl2O2(-) and C2Br2O2(-) and adduct anions Cl- (C2Cl2O2) and Br- (C2Br3O2) were observed but are not primary attachment products. G2 and G3 theories were applied to determine geometries of products and energetics of the electron attachment and ion-molecule reactions studied. Electron attachment to both oxalyl halide molecules leads to a shorter C-C bond and longer C-Cl bond in the anions formed. Trans and gauche conformers of the neutral and anionic oxalyl halide species have similar energies and are more stable than the cis conformer, which lies 100-200 meV higher in energy. For C2Cl2O2, C2Cl2O2(-), and C2Br2O2(-), the trans conformer is the most stable conformation. The calculations are ambiguous as to the oxalyl bromide geometry (trans or gauche), the result depending on the theoretical method and basis set. The cis conformers for C2Cl2O2 and C2Br2O2 are transition states. In contrast, the cis conformers of the anionic oxalyl halide molecules are stable, lying 131 meV above trans-C2Cl2O2(-) and 179 meV above trans-C2Br2O2(-). Chien et al. [J. Phys. Chem. A 103, 7918 (1999)] and Kim et al. [J. Chem. Phys. 122, 234313 (2005)] found that the potential energy surface for rotation about the C-C bond in C2Cl2O2 is "extremely flat." Our computational data indicate that the analogous torsional surfaces for C2Br2O2, C2Cl2O2(-), and C2Br2O2(-) are similarly flat. The electron affinity of oxalyl chloride, oxalyl bromide, and phosgene were calculated to be 1.91 eV (G3), and 2.00 eV (G2), and 1.17 eV (G3), respectively.     

Reactions of amidines with oxalyl chloride. II

Unsubstituted, N-alkyl(aryl)- and N-chloroamidines react with oxalyl chloride to form imidazolidine-4, 5-diones. The hydrochlorides of 1-aryl-2-alkyl(aryl)imidazolidine-4, 5-diones decompose thermally to give N-arylimidoyl isocyanates which change immediately to 4-quinazolones.     

Photoinduced gelation by stilbene oxalyl amide compounds

Oxalyl amide derivatives bearing 4-dodecyloxy-stilbene as a cis-trans photoisomerizing unit were synthesized. The trans derivative acted as a versatile gelator of various organic solvents, whereas the corresponding cis derivative showed a poor gelation ability or none at all. In diluted solution (c = 2.0 x10(-5) mol dm(-3), ethanol), the cis isomer was photochemically converted into the trans isomer within 4 min. Depending on the radiation wavelength, the trans isomer was stable or liable to photodecomposition. When exposed to irradiation, a concentrated solution of the cis isomer (c = 2.0 x 10(-2) mol dm(-3), ethanol) turned into a gel. The FT-Raman, FT-IR, and 1H NMR spectra demonstrated that the gelation process occurred because of a rapid cis --> trans photoisomerization followed by a self-assembly of the trans molecules. Apart from the formation of hydrogen bonding between the oxalyl amide parts of the molecules, confirmed by FT-IR spectroscopy, it was assumed that the pi-pi stacking between the trans-stilbene units of the molecule and a lipophilic interaction between long alkyl chains were the interactions responsible for gelation.     

Comment on the assignments of some vibrational bands of oxalyl fluoride

In view of existing contradictory assignments of the symmetrical stretching vibrations associated with the formal C-C and C-F bonds of trans/cis oxalyl fluoride, an additional theoretical analysis of the corresponding calculated wavenumbers was preformed on trans-C₂O₂F₂ and cis-C₂O₂F₂ based on previously calculated ab initio scaled force fields at the HF/6-31G computational level and new force fields calculated at the MP2/aug-cc-pVTZ level. This novel analysis included computational data from the isotopic shifts brought about by incorporating ¹³C and ¹⁴C atoms into the structure. A detailed examination of the calculated wavenumbers made it possible to validate the assignments of the ν₂ and ν₃ wavenumbers in the trans-C₂O₂F₂ and cis-C₂O₂F₂ molecules as the formal C-C bond stretching and the formal C-F bond symmetrical stretching vibrations, respectively.     

Reaction of substituted 5-aminopyrimidines with oxalyl chloride

Depending on the reaction conditions and the substituents, N-(2,4,6-substituted 5-pyrimidinyl)oxamyl chlorides and N,N-di(2,4,6-substituted 5-pyrimidinyl)oxamides are formed in the reaction of 5-aminopyrimidines with oxalyl chloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 536–538, April, 1976.     

Dichlorination of olefins with diphenyl sulfoxide/oxalyl chloride

Abstract

The combination of diphenyl sulfoxide and oxalyl chloride was used to accomplish the dichlorination of olefins, in which chlorodiphenylsulfonium salt generated in situ was proposed to be the real active species as a chloronium ion source.     

Reactions of oxalyl chloride with 1,2-cycloalkanediols in the presence of triethylamine

The relationship between the product patterns and the configurations of 1,2-cycloheptane- and 1,2-cyclooctanediols 9 in the cyclocondensations with oxalyl chloride in the presence of triethylamine at 0 degrees C has been shown analogous to that obtained for 1,2-disubstituted acyclic ethylene glycols 1: cis-1,2-cyclooctanediol (9f) produced the cyclic oxalate 14f as the major product, while trans-1,2-cycloheptanediol (9e) and trans-1,2-cyclooctanediol (9g) formed the cyclic carbonates 12e, g as the major products. On the other hand, the cyclic oxalates 14a-d were formed as the major products from 1,2-cyclopentane- and 1,2-cyclohexanediols regardless of the configuration. These results can be accounted for by assuming the boat-like transition states for cyclizations of the half esters of comparatively rigid five- and six-membered diols 9a--d. The cyclic oxalates 14a, c may be directly formed through the resulting tetrahedral intermediates from cis-diols (9a,c), and the cyclic carbonates 12a,c as the minor products after ring inversion of the tetrahedral intermediates. The tetrahedral intermediates from the trans-isomers 9b, d cannot undergo ring inversion, producing no traces of the cyclic carbonates 12b, d.     

Reaction of enamines of the isocholine and phenanthridine series with oxalyl chloride

Compounds of the 2,3-dioxopyrrolo[2, 1-a]isoquinoline and 2,3-dioxopyrrolo[1, 2-f]phenanthridine series were synthesized and the products of their condensation with o-phenylenediamine were obtained.Institute of Applied Chemistry, Ural Branch, Russian Academy of Sciences, Perm' 614600. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 946–949, July, 1994. Original submitted January 10, 1994.     

The extremely flat torsional potential energy surface of oxalyl chloride

The conformational behavior of oxalyl chloride has been investigated using ab initio Hartree-Fock (HF) and second-order Moller-Plesset (MP2) perturbation theories, and the coupled-cluster singles and doubles method appended with a perturbative inclusion of connected triple excitations [CCSD(T)]. Correlation consistent polarized valence quadruple-zeta (cc-pVQZ) and quintuple-zeta (cc-pV5Z) basis sets were used in this research. At the cc-pVQZ and cc-pV5Z HF levels, there is no stationary point corresponding to a stable gauche conformer. On the other hand, at the cc-pVQZ and cc-pV5Z MP2 levels and with the cc-pVQZ CCSD(T) method, the gauche conformer of oxalyl chloride was found at O[Double Bond]C-C[Double Bond]O dihedral angles of 81.9 degrees , 79.4 degrees , and 83.4 degrees , respectively. At the cc-pV5Z MP2 level, the energy barrier from trans to gauche was predicted to be 0.74 kcal mol(-1) and that from gauche to trans to be 0.09 kcal mol(-1). Thus, the potential-energy surface along the O[Double Bond]C-C[Double Bond]O torsional mode is exceedingly flat. The existence of the gauche conformation is mainly due to the minimization of steric repulsion.     

The oxysulfenylation of alkenes with dimethyl sulfoxide/oxalyl chloride

A convenient method for the oxysulfenylation of alkenes using dimethyl sulfoxide/oxalyl chloride is described. Cycloalkenes give trans-adducts stereospecifically. The reactions of styrene are highly regioselective for Markovnikov adducts, whereas aliphatic alkenes lead to anti-Markovnikov adducts mainly.