- Rate and product studies in the solvolyses of two cyclic phosphorochloridate esters
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Kinetic and product studies of the solvolyses of acyclic phosphorochloridates are extended to two cyclic diesters, 2-chloro-1,3,2- dioxaphospholane-2-oxide (1) and 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphorinane- 2-oxide (2). Slightly faster solvolyses are observed for 1 than for the acyclic dimethyl phosphorochloridate (3), and 2 solvolyzes somewhat slower than 3. An extended Grunwald-Winstein equation treatment shows similar sensitivities to changes in solvent nucleophilicity and solvent ionizing power for 1, 2, and 3, and a concerted SN2 attack is proposed in each case. Product studies for the solvolyses of 2 in aqueous alcohols are presented. [image presented]. Copyright Taylor & Francis Group, LLC.
- Koh, Han Joong,Kang, Suk Jin,Kevill, Dennis N.
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scheme or table
p. 1404 - 1415
(2010/08/21)
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- New aspects connected with the synthesis of H-phosphinate anhydrides
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A novel reaction between sodium salt of phenylphosphinic acid PhP(O)(OH)H (1) and various phosphorus electrophiles, R2P(O)C1 (2; R = alkyl, aryl, alkoxy or aryloxy) has been described. The presented reaction showed a high selectivity (yield up to 96%) in the products of the symmetric phosphorus anhydrides, R2P(O)-O-(O)PR2(4), which preferentially come from the starting phosphorus electrophiles (2). The results demonstrate that the phosphorus-phosphorus mixed anhydrides, RPH(O)-O-(O)PR2(3) are unstable under basic condition and possibly decomposed with expulsion of a phosphinylidene (Ph-P=O) fragment (6).
- Nycz
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experimental part
p. 589 - 594
(2009/12/26)
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- Reaction mechanism studies of solvolytic displacement of chloride from phosphorus
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The extended Grunwald-Winstein equation is applied to solvolytic displacement at phosphorus. Previous studies of the solvolyses of phosphorochloridates (RO)2POCl, Ph2POCl and [(CH3)2N]2POCl are extended to cyclic phosphorochloridates, with five and six me
- Koh, Han Joong,Kang, Suk Jin,Kevill, Dennis N.
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body text
p. 364 - 368
(2009/04/04)
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- The reactions of dialkyl phosphites and phosphine oxides with iodosylbenzene
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The reaction of iodosylbenzene with > P(O)H type of acids (dialkyl phosphites, secondary phosphine oxides) was studied. The acids of >P(O)H type add to iodosylbenzene to yield intermediate 6 which in the aprotic solvents yields oxidation products, it means >P(O)OH acids and/or anhydride of >P(O)OP(O) P(O)OR ester is the major product.
- Makowiec, Slawomir,Rachon, Janusz
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p. 941 - 955
(2007/10/03)
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- Phosphorochloridates from phosphorohydrazides with ButOCl: Stereospecificity, selectivity and phosphorylium ion intermediates
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The efficiency with which a six-membered cyclic phosphorochloridate can be obtained from the corresponding hydrazide with retention of configuration at phosphorus, using tert-butyl hypochlorite in tert-butyl alcohol, depends on how stereoelectronic factors influence the fate of an intermediate chloride-phosphorylium ion pair.
- Harger, Martin J.P
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p. 6749 - 6752
(2007/10/03)
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- N-BENZOYL O,O-DIALKYL PHOSPHORANILIDATES: REACTION WITH O- AND N-NUCLEOPHILES
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Solvolysis of mixed phosphoric-carboxylic N-phenylimides occurs with exclusive attack of nucleophiles at the carbonyl carbon centre and is accompanied by phosphoryl N->O migration.
- Baraniak, Janina,Stec, Wojciech J.
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p. 4193 - 4196
(2007/10/02)
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- Organophosphorus Antioxidants. X. The Hydroperoxide Decomposing Action of Phosphites, Phosphonites and Thiophosphites
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The kinetics and mechanism of reactions of phosphites, phosphonites, thiophosphites and hydrogenphosphites with cumyl (CHP), t-butyl (TBHP) and α-tetralyl (THP) hydrogenperoxides has been studied by means of (31)P-n.m.r. spectroscopy, high performance liquid chromatography and iodometric titration.All three valent phosphorus compounds studied initially react with hydroperoxides stoichiometrically to give the corresponding P=O products and alcohol.Some species are able to decompose cumyl hydroperoxide catalytically to form phenol and aceton.Acyloin phosphites decompose CHP catalytically after a stoichiometric reaction as thiophosphites do.Tetramethylpiperidinyl phosphites ("HALS-phosphites") react with hydroperoxides only stoichiometrically but with high velocity.Phosphonites react with hydroperoxides in the same way as the corresponding phosphites.Their reactivity, however, is much higher.Hydrogenphosphites are less reactive than phosphites in the reaction with hydroperoxides.They are able to act catalytically.
- Koenig, T.,Habicher, W. D.,Schwetlick, K.
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p. 913 - 922
(2007/10/02)
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- Nitrones. 6. Reactions of Nitrones with Cyclic Phosphonates. Influence of the Phosphonate Ring Size upon the Course of the Reaction
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Nitrones, 5,5-dimethyl-Δ1-pyrroline N-oxide (5), and 3,4-dihydroisoquinoline N-oxide (6) were reacted with the five-membered cyclic phosphonates 2--2-oxo-4,5-dimethyl-1,3,2-dioxaphospholane (1) and 2-(cyanomethyl)-2-oxo-4,5-dimethyl-1,3,2-dioxaphospholane (2) and with the six-membered cyclic phosphonates 2--2-oxo-5,5-dimethyl-1,3,2-dioxaphosphorinane (3) and 2-(cyanomethyl)-2-oxo-5,5-dimethyl-1,3,2-dioxaphosphorinane (4).The reactions of the five-membered phosphonates gave aziridines as products, except that of 6 and 2.The reactions of the six-membered phosphonates gave exclusively or predominantly enamines.The reactions of C-phenyl-N-methylnitrone (7) with 2 gave only trans-1-methyl-2-cyano-3-phenylaziridine (22).Cyclic phosphates 2-hydroxy-2-oxo-4,5-dimethyl-1,3,2-dioxaphospholane (20) and 2-hydroxy-2-oxo-5,5-dimethyl-1,3,2-dioxaphosphorinane (21) were isolated as byproducts from the reactions of the corresponding phosphonates.
- Zbaida, Shmuel,Breuer, Eli
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p. 1073 - 1077
(2007/10/02)
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