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711.
Zsuzsa M. Jszay Gyrgy M. Keser Gyrgy Clementis Imre Petnehzy Katalin Kovts Lszl Tke 《Heteroatom Chemistry》2001,12(2):90-96
Starting from a cyclopropane lactone 5 , the synthesis of a 1‐aminocyclopropane‐1‐phosphonic acid derivative 11 is described. The considerable differences in the reactivity of the lactone ring opening in the case of a cyclopropane lactone substituted by a phosphonic acid ester 5 and their carboxylic acid ester analogue 2 toward ammonia or amines have been compared and interpreted by using the map of electrostatic potentials. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:90–96, 2001 相似文献
712.
Synthesis of the P-sulfide derivatives of 3-phosphabicyclo[3.1.0]hexanes and 1,2-dihydrophosphinines
Gyrgy Keglevich Lszl Tke Csaba Lovsz Klmn Újszszy Gbor Szalontai 《Heteroatom Chemistry》1994,5(4):395-401
Several 3-phosphabicyclo[3.1.0]hexane 3-oxides have been transformed into the corresponding sulfides by reaction with phosphorus pentasulfide. The 3-phenyl derivative could also be prepared by deoxygenation of the oxide followed by reaction with elemental sulfur. Opening of the cyclopropane ring in phosphabicyclohexane sulfides afforded mixtures of 3- and 5-methyl-1,2-dihydro-phosphinine-1-sulfides. Because of better yields, preparation of these products by thionation of the dihydrophosphinine oxides is more appropriate. The new phosphorus heterocycles have been characterized by 31P, 13C, and 1H NMR and mass spectral data. 相似文献
713.
Preparative‐scale photolyses of the title triisopropylphenyl‐substituted compounds 1 and 4 at 254 nm, in the presence of alcohols, led to aryl‐H‐phosphinates 3 in good yields. Reaction of the tri‐tert‐butylphenyl derivative 5 was, however, accompanied by side reactions. The results of two series of competitive reactions are consistent with a mechanism involving a five‐coordinate adduct 8 of the alcohol on the P=O group of the phosphanorbornene oxides. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:6–9, 2001 相似文献
714.
György Keglevich János Kovács Tamás Körtvélyesi Gyula Parlagh Tímea Imre Krisztina Ludányi László Hegedűs Miklós Hanusz Kálmán Simon Andrea Márton György Marosi László Tőke 《Heteroatom Chemistry》2004,15(2):97-106
The [4 + 2] cycloaddition of the double-bond isomers ( A and B ) of dihydrophosphinine oxide 1 afforded novel phosphabicyclo[2.2.2]oct-5-ene derivates ( 2–4 ), formation of which was justified by PM3 semiempirical calculations. The compounds of dimer type ( 2–4 ) were utilized in the UV light-mediated fragmentation-related phosphinylation of nucleophiles, especially in that of alcohols. To explore the role of structural modifications on the fragmentation ability, disulfide 5 , phosphabicyclooctane 7 obtained by the hydrogenation of 2 , and the adduct of dihydrophosphinine oxide 1 with benzoquinone ( 7 ) were also synthesized and tested in fragmentation. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:97–106, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10221 相似文献
715.
The reaction of dialkylphosphinous chlorides ( 1 ) with arylmagnesium bromides carried out in the air atmosphere was found to afford aryl‐dialkylphosphine oxides ( 2 ) and aryl dialkylphosphinates ( 3 ) in a comparable quantity. Formation of the latter product ( 3 ) is the first example that an aryl‐dialkylphosphine, formed as an intermediate, is autooxidized to the corresponding phosphinate. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:38–41, 2001 相似文献
716.
Gyrgy Keglevich Jnos Kovcs ron Szllsy Attila Kovcs Andrea Szab Krisztina Ludnyi Istvn Kdas Lszl Tke 《Heteroatom Chemistry》2003,14(1):29-35
In the presence of tetracyanoethylene, the reaction of two molecules of dihydrophosphinine oxide 2B followed an unexpected route to afford diphosphatricyclododecatrienes 4 instead of the corresponding Diels–Alder cycloadducts ( 3 ). Structures of the products ( 4 ) have been elucidated by a joint application of spectroscopy and quantum chemical calculations. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:29–35, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10062 相似文献
717.
Gyrgy Keglevich Lszl Tke Zsolt Bcskei Dra Menyhrd Louis D. Quin 《Heteroatom Chemistry》1995,6(6):593-595
The first X-ray structure of a phosphabicyclooctadiene, together with the NMR and mass spectral characterization of its isomers, is reported. © John Wiley & Sons, Inc. 相似文献
718.
Peter Bak Laszl Fenichel Laszl T
ke Bruce E. Davison Alpana Patel 《Heteroatom Chemistry》1994,5(4):415-419
The synthesis of bis-(1,2-O-isopropylidene-6-O-triphenylmethyl-α-D-glucofuranosyl)-20-crown-6 ( 1 ) and its complexing ability with alkali and ammonium cations are described. The crown ether 1 was synthesized in a stepwise manner via the “half-crown” ( 2 ) using a blocking-deblocking procedure, in which the 3,3′-bridge was formed, followed after suitable manipulations, by formation of the 5,5′-bridge. An unusual feature of the complexing ability of the crown ether is that, although potassium and ammonium ions most closely approach the size of the complexing cavity, it is the sodium ion which forms the most stable complex. Compound 1 does not show chiral recognition toward two alkylammonium salts. 相似文献
719.
Gyrgy Keglevich Attila Kovcs Lszl Tke Klmn Újszszy Gyula Argay Mtys Czugler Alajos Klmn 《Heteroatom Chemistry》1993,4(4):329-335
Preparation of P-amino-3-phosphabicyclo[3.1.0]-hexane 3-oxides either by addition of dichlorocarbene to the double bond of 1-amino-2,5-dihydro-1H-phosphole 1-oxides or by substitution of the P-chloro derivative of the bicyclic system was accomplished. Two different diastereomers are obtained by the two approaches; their 13C NMR spectra were interpreted on the basis of the P-ethoxy isomers, whose structures were confirmed by X-ray analysis. The P-hydroxy adduct was also prepared, and it was found that intermolecular O H … O hydrogen bonding connects the molecules together in the solid phase. This effect eliminates the possibility of diastereoisomerism, as was also observed in the case of P-hydroxy tetrahydrophosphinine oxides. Thermolysis of the P-hydroxy adduct is a better way to synthesize 1-hydroxy-1,2-dihydrophosphinine oxides than by hydrolysis of the phosphinic chlorides. 相似文献