- Preparation and Characterization of Parent Phenylphosphinidene and Its Oxidation to Phenyldioxophosphorane: The Elusive Phosphorus Analogue of Nitrobenzene
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Triplet phenylphosphinidene was prepared by light-induced elimination of ethylene from the corresponding phenylphosphirane and was characterized by IR and UV/vis spectroscopy together with matching of its spectral data with density functional theory computations. The photolysis of phenylphosphirane in 3P-O2 doped matrices enabled the spectroscopic identification of a hitherto unknown phenyldioxophosphorane, the long elusive phosphorus analogue of nitrobenzene.
- Mardyukov, Artur,Niedek, Dominik,Schreiner, Peter R.
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supporting information
p. 5019 - 5022
(2017/05/04)
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- An efficient, multiply promiscuous hydrolase in the alkaline phosphatase superfamily
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We report a catalytically promiscuous enzyme able to efficiently promote the hydrolysis of six different substrate classes. Originally assigned as a phosphonate monoester hydrolase (PMH) this enzyme exhibits substantial second-order rate accelerations ((kcat/KM) /k w), ranging from 107 to as high as 1019, for the hydrolyses of phosphate mono-, di-, and triesters, phosphonate monoesters, sulfate monoesters, and sulfonate monoesters. This substrate collection encompasses a range of substrate charges between 0 and -2, transition states of a different nature, and involves attack at two different reaction centers (P and S). Intrinsic reactivities (half-lives) range from 200 days to 105 years under near neutrality. The substantial rate accelerations for a set of relatively difficult reactions suggest that efficient catalysis is not necessarily limited to efficient stabilization of just one transition state. The crystal structure of PMH identifies it as a member of the alkaline phosphatase superfamily. PMH encompasses four of the native activities previously observed in this superfamily and extends its repertoire by two further activities, one of which, sulfonate monoesterase, has not been observed previously for a natural enzyme. PMH is thus one of the most promiscuous hydrolases described to date. The functional links between superfamily activities can be presumed to have played a role in functional evolution by gene duplication.
- Van Loo, Bert,Jonas, Stefanie,Babtie, Ann C.,Benjdia, Alhosna,Berteau, Olivier,Hyvoenen, Marko,Hollfelder, Florian
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scheme or table
p. 2740 - 2745
(2010/10/03)
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- Fragmentation of a phenylphosphonamidic acid as a new technique for the generation of phenyl dioxophosphorane
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N-(1-Adamantyl) phenylphosphonamidic acid (3), an easily prepared solid, on heating in toluene or 1,2-dichloroethane gave the crystalline adamantylamine salt of the anhydride PhP(O)(NHAd)-O-PPh(O)(OH). The mechanism is proposed to involve first the fragmentation of 3 to form phenyl dioxophosphorane, PhPO2, which then acts as a phosphorylating agent to unreacted 3. This mechanism was supported by the observation of first-order kinetics for the consumption of 3. When the phosphonamidic acid was fragmented in the presence of an alcohol, the intermediate PhPO2 was trapped as the monoalkyl phenylphosphonate. The OH groups on the surface of silica gel were also phosphonylated by PhPO2. The acidic OH group of a phosphoric acid monoester (thymyl phosphate) was phosphonylated to give Thy-O-P(O)(OH)-O-PPh(O)(OH). It is concluded from this study that N-(1-adamantyl) phenylphosphonamidic acid is a useful precursor of phenyl dioxophosphorane, which can perform valuable phosphonylation operations.
- Quin, Gyoengyi Szakal,Jankowski, Stefan,Quin, Louis D.
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