- 1,3-Dimethyl-2-(3-nitro-1,2,4-triazol-1-yl)-2-pyrrolidin-1-yl-1,3, 2-diazaphospholidinium hexafluorophosphate (MNTP): A powerful condensing reagent for phosphate and phosphonate esters
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A novel phosphonium-type condensing reagent, 1,3-dimethyl-2-(3-nitro-1,2,4- triazol-1-yl)-2-pyrrolidin-1-yl-1,3,2-diazaphospholidinium hexafluorophosphate (MNTP), was designed and synthesized. A 31P NMR study on the condensation reactions of ph
- Oka, Natsuhisa,Shimizu, Mamoru,Saigo, Kazuhiko,Wada, Takeshi
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Read Online
- Phosphoramidite ligand, catalyst and method for preparing 4-acetoxyl butaldehyde
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The invention provides a phosphoramidite ligand, a catalyst and a method for preparing 4-acetoxyl butaldehyde. The phosphoramidite ligand has the following structural formula (I) as shown in the specification. In the formula, the various groups R in the formula (I) are the same or different; and the various groups R are respectively independently selected from C1-C6 alkyl fragments or C6-C10 aryl-containing fragments. The catalyst containing the phosphoramidite ligand provided by the invention has the characteristics of being high in catalytic activity, easy to recycle and the like. Moreover,the 4-acetoxyl butaldehyde is prepared by adopting the catalyst disclosed by the invention and has high conversion ratio and yield.
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Paragraph 0055; 0058
(2018/04/28)
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- Total synthesis of alkaloid 205B
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Concise and highly stereocontrolled total syntheses of racemic and enantiopure frog alkaloid 205B (1) were accomplished in 11 steps from 4-methoxypyridines 6 and 7 in overall yields of 8 and 8%, respectively. The assembly of the core of the natural product relies on a stereoselective Tsuji-Trost allylic amination reaction and a ring-closing metathesis. The synthesis features the use of an N-acylpyridinium salt reaction to introduce the first stereocenter and an unprecedented trifluoroacetic anhydride-mediated addition of an allylstannane to a vinylogous amide with complete facial selectivity. Deoxygenation of the C4 ketone proved difficult but was accomplished via a modified Barton-McCombie reaction in the presence of a catalytic amount of diphenyl diselenide.
- Tsukanov, Sergey V.,Comins, Daniel L.
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supporting information
p. 9074 - 9085
(2015/02/19)
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- Total synthesis of Jerangolid A
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(Figure Presented) The first total synthesis of the antifungal polyketide jerangolid A has been accomplished. Starting with the readily available (R)-Roche ester and (S)-glycidol as chirons, the synthesis involved a highly syn-selective Lewis acid catalyz
- Hanessian, Stephen,Focken, Thilo,Oza, Rupal
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supporting information; experimental part
p. 3172 - 3175
(2010/09/05)
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- A divergent synthesis of minor groove binders with tail group variation
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A new synthesis of polyamide minor groove binders in which diversity is introduced by the nucleophilic substitution of a 2-sulfido-1,3,2- diazaphospholidinyloxy substituent by volatile secondary amine nucleophiles is described. Such a method has potential
- Breen, David,Kennedy, Alan R.,Suckling, Colin J.
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experimental part
p. 178 - 186
(2009/04/07)
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- IONIC LIQUID CONTAINING PHOSPHONIUM CATION HAVING P-N BOND AND METHOD FOR PRODUCING SAME
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An ionic liquid which contains an organic matter represented by the following general formula (1) as a cation component. The ionic liquid is stably in a liquid state over a wide temperature range and is excellent in electrochemical stability. The ionic liquid is advantageously used for applications such as electric power storage devices, lithium secondary batteries, electrical double layer capacitors, dye-sensitized solar cells, fuel cells, and reaction solvents.
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Page/Page column 17; 18
(2008/12/07)
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- Synthesis and characterization of diaminodithio- and aminotrithiophosphoric acid esters
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The synthesis and characterization of a series of five new diaminodithiophosphoric acid esters (R1R2N)2P(S)SR and five new aminotrithiophosphoric acid esters (R1R2N)P(S)(SR)2 are described. The structure of two of these compounds, the diaminodithio deriva
- Marchand, Patrice,Meffre, Anca,Donnadieu, Bruno,Taton, Daniel,Gnanou, Yves,Destarac, Mathias,Leising, Frederic,Caminade, Anne-Marie,Majoral, Jean-Pierre
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p. 1233 - 1244
(2008/02/05)
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- Effect of amino substituents on the stereochemical outcome of the photo-arbuzov rearrangements of 1-arylethyl phosphorodiamidites
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The essentially stereochemically pure 1-arylethyl phosphorodiamidites 8 and 9 were irradiated by UV light in acetonitrile, benzene, and cyclohexane (Tables 1-4). Reaction via singlet free-radical pairs, formed by carbon-oxygen bond scission (Scheme 1), wh
- Bhanthumnavin, Worawan,Bentrude, Wesley G.
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p. 4643 - 4651
(2007/10/03)
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- Carbonyl Phosphorylation via N,3E>-Bifunctional Reagents. Probing Mechanistic and Reactivity Features through Chemical and Isotopic Labelling
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A range of organophosphorus(III) esters of the general form PX(SiR3)n has been prepared via reaction of PCl with R3SiOH or LiN(SiMe3)2 respectively.These esters will phosphonylate aldehydes via the Abramov reaction to afford α-siloxyphosphonate esters cleanly and in high yields.The mechanism of the Abramov reaction using POSiR3 reagents has been investigated by (i) 18O isotopic labelling experiments which reveal that reaction proceeds with exclusive rather than bond cleavage which, in turn, supports a mechanism with overall retention of configuration at phosphorus, (ii) double crossover experiments which support intramolecular silyl group transfer and (iii) manipulations of the electron-donating properties of the carbonyl substrate which suggest that bond formation is rate determining.Further tuning of the phosphonylation reaction is possible by manipulating (a) the nature of the phosphorus-coordinated donor atoms in the chelate ring, (b) the size and rigidity of the chelate ring, (c) the ester residue donor atom X and (d) the silicon substituents R.
- Devitt, Paul G.,Kee, Terence P.
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p. 3169 - 3182
(2007/10/02)
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- The Synthesis by Phosphoramidite Methodology of Novel Phospholipids Related to Ethylenediamine
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Novel phospholipid analogues related to ethylenediamine have been prepared by a rapid three-step procedure.The diazaphosphacyclopentane (1) reacts with alcohols to yield phosphoramidites in high yield.These are oxidised to the phosphates with N2O4.The phosphates undergo a single P-N cleavage under conditions of acid catalysis to yield phospholipid analogues, similar in phosphate structure to natural phospholipids, but a single substitution of N for O.Full spectroscopic and analytical data are presented and discussed.
- Anson, Michael S.,McGuigan, Christopher
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p. 715 - 720
(2007/10/02)
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- Synthesis of some Nucleoside Cyclic Phosphoramidates and related compounds via Phosphoramidites
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Reaction of 2-chloro-3-methyl-1-oxa-3-aza-2-phosphacyclopentane with thymidine and with 2'-deoxy-5-fluorouridine gave their 3',5'-bis-O-(3-methyl-1-oxa-3-aza-2-phosphacyclopentan-2-yl) derivatives (5) and (6).Reaction of these nucleosides with 2-chloro-1,3-dimethyl-1,3-diaza-2-phosphacyclopentane gave 3',5'-bis-O-(1,3-dimethyl-1,3-diaza-2-phosphacyclopentan-2-yl) derivatives (7) and (8).The phosphoramidites, (7) and (8) were oxidised with dinitrogen tetroxide to the corresponding phosphoramidates (9) and (10).Attempts to oxidise (5) and (6) in a similar way resulted in opening of the phosphoramidate ring.Treatment of compounds (5)-(8) with sulphur gave the corresponding phosphorothioamidates (11)-(14).The hydrolysis of 3',5'-bis-O-(1,3-dimethyl-2-oxo-1,3-diaza-2-phosphacyclopentan-2-yl)thymidine (9) was studied using (31)P n.m.r. spectroscopy.At pH 7.0 and 25 deg C the half-life was 21 h.Both phosphorus heterocyclic rings opened at the same rate.The hydrolysis of the second ring proceeded at ca. three times the rate of hydrolysis of the first. 2'-Deoxy-5-fluoro-3',5'-bis-O-(1,3-dimethyl-2-oxo-1,3-diaza-2-phosphacyclopentan-2-yl)-uridine (10) did not inhibit isolated purified zhymidylate synthetase and was only a weak inhibitor of leukemia L1210 cell growth.
- Jones, A. Stanley,McGuigan, Christopher,Walker, Richard T.
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p. 199 - 202
(2007/10/02)
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- PREPARATION AND STRUCTURAL STUDIES OF A NUMBER OF HETEROCYCLIC PHOSPHORANES
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A series monocyclic five-membered ring containing trivalent phosphorous compound with oxygen, nitrogen and sulfur bonded to phosphorous, in various combinations has been allowed to react with trifluoroethyl and 1,1,1,3,3,3-hexafluoroisopropyl benzenesulfenates.In some cases, pentacoordinated phosphorous compounds resulted.These materials have been studied by various NMR techniques.The same trivalent phosphorous compounds were allowed to react with 3,4-(bistrifluoromethyl)1,2,dithiete.In some cases phosphoranes were formed and they were also studied by NMR.
- Denney, Donald B.,Denney, Dorothy Z.,Liu, Lun-Tsu
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