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V. F. Mironov A. T. Gubaidullin L. M. Burnaeva I. A. Litvinov G. A. Ivkova S. V. Romanov T. A. Zyablikova A. I. Konovalov I. V. Konovalova 《Russian Journal of General Chemistry》2004,74(1):32-47
2-Alkoxy-4-oxo-5,6-benzo-1,3,2-dioxaphosphorinanes containing an electron-withdrawing fluorinated exocyclic substituent at the P atom react with aromatic aldimines to give 6,7-benzo-1,4,2-oxaza- phosphepines with a high regio- and stereoselectivity. The major diastereomers were isolated, and their configuration was determined by single crystal X-ray diffraction. 相似文献
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Kuznetsov V. V. Brusilovskii Yu. E. Mazepa A. V. Krasnoshchekaya S. P. 《Russian Journal of General Chemistry》2001,71(1):150-150
Russian Journal of General Chemistry - 相似文献
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Irina V. Konovalova Liliya M. Burnaeva Vladimir F. Mironov Sergey V. Romanov Gulnara A. Ivkova Aidar T. Gubaidullin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract Phosphorus (111) containing dcrivatives of salicylic acid easily react with carbonyl compounds with formation of cycloexpansion products - 1,3,2- or 1,4,2-dioxaphosphepines. For the first time we have shown that dialkyl-l-oxólkylphosphonates react with 2-R-4-oxo-5,5-benzo-1,3,2-dioxaphosphorinanes and yield 1,3,2-dioxaphosphepines (I) with high stereoselectivity. The configuration of the preferable diastereoisomer (IId) has been determined by X-ray analysis. The hydrolysis of compounds (IIa-c) leads to formation of 2-hydroxy-2-oxo-1,3,2-dioxaphosphepines (III). The structure of phosphepine (IIIb) in crystal is shown on the figure. The work is supported by the Leading Scientific School Foundation of Russia (grant N 96-15-97330) and the Russian Foundation for Basic Research (grant N 98-03-33266). 相似文献
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Mironov V. F. Ivkova G. A. Burnaeva L. M. Konovalova I. V. Musin R. Z. 《Russian Journal of General Chemistry》2003,73(9):1367-1370
The reaction of pyruvonitrile with 2-tetrafluoropropoxy-5,6-benzo-1,3,2-dioxaphosphorinan-4-one results mainly in the enlargement of the starting heteroring to form 4-cyano-4-methyl-2-tetrafluoropropoxy-6,7-benzo-1,3,25-dioxaphosphepin-5-one 2-oxide as a mixture of two diastereomers (14:1) along with minor amounts of 3-cyano-3-methyl-2-tetrafluoropropoxy-6,7-benzo-1,4,25-dioxaphosphepin-5-one 2-oxide. 相似文献
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Roza M. Aminova Grigory A. Shamov Vladimir B. Mushkin Vladimir F. Mironov Alexander I. Konovalov Albert V. Aganov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract Reaction of 2-R-4-oxo-5,6-benzo-1,3,2-dioxaphosphorinanes I with chloral leading to formation of seven-membered heterocycles - 1,4,2-dioxaphosphepines is characterized by the high degree of stereoselectivity. We investigated the model reactions of 2-R-4-oxo-1,3,-dioxaphosphorin-5-enes with CX3CHO by PM3 and ab initio methods in STO-3G, 3-21G, 6-31G*, MP2/6-31G* basis set and also DFT method (B3LYP). 相似文献
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Vladimir F. Mironov Aidar T. Gubaidullin Gulnara A. Ivkova Igor A. Litvinov Boris I. Buzykin Liliya M. Burnaeva 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract [3+2]-Cycloaddition of N,N-dimethylhydrazone benzaldehyde (I) to 2-RFO-4-oxo-5,6-benzo-l,3,2-dioxaphosphorinanes (II) yields the new heterocycle - 2-RFO-4-Me2N-2,5-dioxo-3-phenyl-6,7-benzo- 1,4,2-dioxaphosphepine (III) [RF = C6F5, CH(CF3)2) with high stereoselectivity (above 94%). The reaction is likely to involve the initial interaction of nitrogen as a nucleophile with wbonyl carbon as an electrophile. The hydrolysis of (III) leads to phosphonic acid (IV) (ORF = OH). 相似文献
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Aidar T. Gubaidullin Vladimir F. Mironov Gulnara A. Ivkova Igor A. Litvinov Irina V. Konovalova Liliya M. Burnaeva 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract Hexafluoroacetone imine easily interacts with compounds (I, R = OMe, OCH2CF2CHF2, NEt2, Ph) in two directions unlike hexafluoroacttone and gives 1,4,2-oxazaphosphepines (II) (pathway I) or 1,3,2-oxszaphosphepines (III) (pathway 2). The compound (II) (R = NEt2) lightly hydrolyzes to yield the salt (IV). The structure of heterocycles II-IV) has been confirmed by X-ray analysis (see fig. I, II, R = OMe; fig. 2, IV). The detail structural peculiarities of the compounds am discussed. 相似文献
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I. A. Litvinov O. N. Kataeva V. A. Naumov R. P. Arshinova S. G. Gnevashev 《Russian Chemical Bulletin》1991,40(1):196-198
The seven-membered heterocycle in the crystal structure of 2-phenyl-2-oxo-5,6-benzo-1,3,2-dioxaphosphepine has distorted (asymmetric) twist conformation and the plane of the phenyl substituent at the phosphorus atom does not coincide with the bisector of the plane of the OPO fragment of the heterocycle and is not perpendicular to it.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 214–217, January, 1991. 相似文献
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Solubility and Solution Structure of Cellulose Derivatives 总被引:1,自引:0,他引:1
Walther Burchard 《Cellulose (London, England)》2003,10(3):213-225
Strongly interacting solvents are needed to dissolve cellulose; therefore, in the past the interpretation of the uncommon solution behavior of cellulose and its derivatives was based mainly on energetic (enthalpic) considerations, for example, hydrogen bonding. These attempts have not been very successful. The present paper demonstrates that entropic effects influence the solution behavior much stronger than hitherto supposed. In the well-known Flory–Huggins theory the driving force for dissolution of flexible chains is the configurational entropy of mixing. This large entropy is strongly reduced by the chain stiffness of the cellulose backbone and by the strictly regular primary structure of this polysaccharide. It strongly reduces the driving force for dissolution. The entropy of mixing becomes largely increased again by the attachment of long side chains and causes solubility with surprising efficiency (hairy rod principle). This effect is demonstrated with several examples. Among others, the surprising insolubility of short, regular-selectively substituted cellulose chains is explained, although long chains of the same substitution pattern are soluble. The striking behavior of cellulose ethers in water is based on the hydrophobic effect, which causes an increased order of the polymer surrounding water molecules. The induced order results in a very pronounced decrease of entropy of mixing that overcompensates the positive configurational entropy of mixing. Common rules of basic thermodynamics now predict phase separation on heating, contrary to the Flory–Huggins theory, which can only predict phase separation on cooling. 相似文献