6840-11-5Relevant academic research and scientific papers
(S)-4-tert-Butyl-2-phenyl-2-oxazoline derived palladacycles as efficient catalysts for the decomposition of P=S pesticides
Lu, Zhong-Lin,Yang, Xiao-Sheng,Guo, Zhi-Fo,Wang, Rui-Yao
, p. 2659 - 2672 (2010)
Three palladacycles with N, N-trans coordination, (S)-{2-[2-(4-tert-butyl) oxazolinyl]phenyl-C1, N}(4-R-pyridine)(aqua)npalladium(II) triflate (R = CF 3, n = 1, 1; R = H, n = 0, 2; R = NMe2, n = 1, 3), have been prepared from the respective chloride precursors and were characterized with IR and 1H-NMR and elemental analyses. The crystal structures of 2 and a pincer complex (S, S)-{2, 6-bis[2-(4-iso-propyl)oxazolinyl]phenyl-N, C1, N}bromo-palladium(II) hydrate (5) were determined. For methanolysis of P=S pesticides, it was found that ortho-palladated complexes 1-3 effectively catalyzed the reaction; however, the pincer complex 4 with triflate counterion was much less active. Relative to the methoxide-promoted background reaction at ssPH 10.80, 1 mmol L-1 of palladacycles 1-3 can accelerate the methanolysis by 8.7 × 109, 1.5 × 10 9, and 1.0 × 108-fold, respectively. For racemic P=S pesticides, such as letophos and EPN, it proved that there is no clear chiral discrimination during the catalysis. The reaction mechanism of the catalytic methanolysis was discussed according to the experimental results.
1,2,4-Dithiazole-5-ones and 5-thiones as efficient sulfurizing agents of phosphorus(iii) compounds - A kinetic comparative study
Ponomarov, Oleksandr,Laws, Andrew P.,Hanusek, Ji?í
supporting information, p. 8868 - 8876 (2013/01/15)
The sulfurization efficiency of 25 3-substituted-1,2,4-dithiazole-5-ones and 5-thiones towards triphenyl phosphite in acetonitrile, DCM, THF and toluene at 25 °C was evaluated. All the 1,2,4-dithiazoles are much better sulfurizing reagents than commercially available agents (PADS, TETD, Beaucage's reagent). The most efficient sulfurizing agents in all solvents are 3-phenoxy (4), 3-phenylthio (5) and 3-ethoxy-1,2,4-dithiazole-5-one (1) whose reactivity is at least two orders of magnitude higher than that of other 1,2,4-dithiazoles. Contrary to a previous report, the sulfurization with 1 does not yield carbonylsulfide and ethyl cyanate as the additional reaction products but unstable ethoxythiocarbonyl isocyanate which has been trapped with 4-methoxyaniline. Similar trapping experiments have proven that the site of attack is at the sulfur adjacent to the CO group for compounds 4 and 5. The reaction pathway involves rate-limiting initial nucleophilic attack of the phosphorus at sulfur followed by decomposition of the phosphonium intermediate to the corresponding phosphorothioate and isocyanate/isothiocyanate species. The existence of the phosphonium intermediate during sulfurization of triphenyl phosphine with 3-phenyl-1,2,4-dithiazole-5-thione (7a) was proven using kinetic studies. From the Hammett and Bronsted correlations and from other kinetic measurements it was concluded that the transition-state structure is almost apolar for the most reactive 1,2,4-dithiazoles whereas a polar structure resembling a zwitter-ionic intermediate may be more appropriate for the least reactive 1,2,4-dithiazoles. The extent of P-S bond formation and S-S bond cleavage is very similar in all reaction series but it gradually decreases with the reactivity of the 1,2,4-dithiazole derivatives.
Enantiopure O-substituted phenylphosphonothioic acids: Chiral recognition ability during salt crystallization and chiral recognition mechanism
Kobayashi, Yuka,Morisawa, Fumi,Saigo, Kazuhiko
, p. 606 - 615 (2007/10/03)
The chiral recognition ability of enantiopure O-methyl, O-ethyl, O-propyl, and O-phenyl phenylphosphonothioic acids (1a-d) for various kinds of racemic amines during salt crystallization and the chiral recognition mechanism were thoroughly investigated. T
SYNTHESIS AND NMR SPECTROSCOPIC INVESTIGATION OF PHENYLPHOSPHORYL DERIVATIVES
Duddeck, Helmut,Lecht, Rainer
, p. 169 - 178 (2007/10/02)
The syntheses of 16 phenyl- (1 and 3) and phenylthiophosphoryl (2) derivatives are described.The 13C and 17O NMR data sensitively reflect electron density changes in the phosphoryl substituents caused by p?-d? back-donation from X/Y to P.Taft constants ?1 and ?R0 were derived for 16 phosphoryl substituents.
O,O-Dialkyl Thiophosphoro- and O-Alkyl Phenylthiophosphono-cyanidates: Synthesis and Reactions
Das, Sushanta K.,Balasubrahmanyam, S. N.
, p. 254 - 256 (2007/10/02)
The title compounds (2a-d) have been prepared by the reactions of the corresponding chloridates (1a-d) with potassium cyanide in a two-phase system (dichloromethane-water) in the presence of cetyltrimethylammonium bromide.An unexpected facile conversion of these cyanidates (2a-d) into O,O,O-trialkyl thiophosphates (5a) or O,O-dialkyl phenyl thiophosphonates (5b) has been observed in the presence of aqueous alcoholic potassium hydroxide.
A New Convenient Synthesis of Alkylphenylthiophosphinic Chlorides
Kaushik, M. P.,Vaidyanathaswamy, R.
, p. 932 - 933 (2007/10/02)
A one pot preparation of alkylphenylthiophosphinic chlorides from phenylphosphinous dichloride and ethylenethiourea is described.
Photochemistry of Phospholens. Part 7. Element Effects on the Photofragmentation of 3,4-Dimethyl-1-phenyl-3-phospholen. Phosphinothioylidene
Tomioka, Hideo,Takata, Shyoji,Kato, Yoshio,Izawa, Yasuji
, p. 1017 - 1021 (2007/10/02)
Photolysis of 3,4-dimethyl-1-phenyl-3-phospholen 1-sulphide (1) in methanol afforded, in addition to the expected diene, O-methyl phenylphosphinothioate (3) and OO-dimethyl phenylphosphonothioate (4), whose composition was dependent on irradiation time.Compound (4) was shown to be a photolysis product of (3) in methanol.The rate and stereospecifities of the photo-extrusion of (2) are investigated and compared with that observed in the photofragmentation of the corresponding oxide.In proceeding from the oxide to the sulphide, the stereospecifities decreased in cis-α-methyl derivatives but increased in trans-α-methyl derivatives and the relative reactivities of the fragmentation decreased.
