- New insights into the chemistry of gem-bis(phosphonates): Unexpected rearrangement of Michael-type acceptors
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The use of tetraethyl ethylidenebis(phosphonate) as a Michael acceptor with different nucleophiles was investigated. It was found that in some cases this compound undergoes phosphate removal, depending on the nature of the nucleophile. The chemical behavior of its epoxy derivative tetraethyl oxiranylidenebis(phosphonate) as an electrophile was also studied. This compound underwent a very attractive and remarkable phosphonate-phosphate rearrangement resulting in the enol phosphate 8 regardless of the nucleophile employed. Different mechanistic studies were conducted in an attempt to explain the mechanisms involved. To the best of our knowledge, this reaction constitutes a remarkable novelty, being the first reported rearrangement reaction of an epoxy derivative of a gem-bis(phosphonate). In addition, evidence supporting the involvement of a radical or a polar mechanism, depending on the nature of the nucleophile, is discussed. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Szajnman, Sergio H.,Linares, Guadalupe Garcia,Moro, Pablo,Rodriguez, Juan B.
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Read Online
- Aerobic Allylic Amination Catalyzed by a Pd(OAc)2/P(OPh)3System with Low Catalyst Loading
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A Pd(OAc)2/P(OPh)3 combination catalyzed Tsuji-Trost-Type allylic amination under aerobic conditions. Both aromatic and aliphatic secondary amines were transformed into the corresponding allylic amines with a tiny amount of the catalyst system (typically 0.02 mol % Pd), only when allylic phosphates were employed as electrophiles. Other typical electrophiles, such as allylic acetate and carbonate, were marginally reactive. A Pd(0) complex, Pd[P(OPh)3]3, formed in situ was suggested as an active species by mechanistic experiments.
- Yurino, Taiga,Saito, Sunaho,Ichihashi, Mizuki,Ohkuma, Takeshi
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supporting information
p. 2864 - 2872
(2022/02/14)
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- Synthetic method of asymmetric phosphate compound
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The invention relates to the field of lithium ion batteries, and discloses a synthetic method of an asymmetric phosphate compound. The method comprises the following steps: reacting phosphorus oxychloride represented by a formula (I), a compound represent
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Paragraph 0038-0041; 0042-0045; 0103
(2021/01/29)
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- Tunable Redox Potential Photocatalyst: Aggregates of 2,3-Dicyanopyrazino Phenanthrene Derivatives for the Visible-Light-Induced α-Allylation of Amines
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This work highlights the tunable redox potential of 6,11-dibromo-2,3-dicyanopyrazinophenanthrene (DCPP3) aggregates, which can be formed through physical π-πstacking interactions with other DCPP3 monomers. Electrochemical and scanning electron microscopy showed that the reduction potential of [DCPP3]n aggregates could be increased by decreasing their size. The size of [DCPP3]n aggregates could be regulated by controlling the concentration of DCPP3 in an organic solvent. As such, a fundamental understanding of this tunable redox potential is essential for developing new materials for photocatalytic applications. The [DCPP3]n aggregates as a visible-light photocatalyst in combination with Pd catalysts in the visible-light-induced α-allylation of amines were used. This [DCPP3]n photocatalyst exhibits excellent photo- and electrochemical properties, including a remarkable visible-light absorption, long excited-state lifetime (16.6 μs), good triplet quantum yield (0.538), and high reduction potential (Ered([DCPP3]n/[DCPP3]n-) > -1.8 V vs SCE).
- Bao, Ming,He, Min,Wang, Yi,Yu, Xiaoqiang
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p. 14720 - 14731
(2021/11/16)
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- Ene-Yne Metathesis of Allylphosphonates and Allylphosphates: Synthesis of Phosphorus-Containing 1,3-Dienes
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A variety of ene-yne cross metathesis reactions were performed using unsaturated phosphonate and phosphate reagents, affording the corresponding phosphorylated 1,3-diene products in good to excellent yields. These difficult ene-yne metatheses employed a Grubbs catalyst bearing a cyclic amino alkyl carbene ligand. A variety of terminal alkynes of varying substitution underwent the reaction, and different phosphorus-containing alkenes were found to give the conjugated diene products in high yields. The resulting dienes were further transformed by Horner-type Wittig reactions and a Diels-Alder cycloaddition.
- Rohde, Laurence N.,Wild, Thérèse H.,Diver, Steven T.
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p. 1371 - 1384
(2021/02/05)
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- Synthesis of Cyclic Enones by Allyl-Palladium-Catalyzed α,β-Dehydrogenation
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The use of allyl-palladium catalysis for the one-step α,β-dehydrogenation of ketones via their zinc enolates is reported. The optimized protocol utilizes commercially available Zn(TMP)2 as base and diethyl allyl phosphate as oxidant. Notably, this transformation operates under salt-free conditions and tolerates a diverse scope of cycloalkanones.
- Huang, David,Zhao, Yizhou,Newhouse, Timothy R.
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supporting information
p. 684 - 687
(2018/02/09)
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- Tandem Palladium and Isothiourea Relay Catalysis: Enantioselective Synthesis of α-Amino Acid Derivatives via Allylic Amination and [2,3]-Sigmatropic Rearrangement
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A tandem relay catalytic protocol using both Pd and isothiourea catalysis has been developed for the enantioselective synthesis of α-amino acid derivatives containing two stereogenic centers from readily accessible N,N-disubstituted glycine aryl esters and allylic phosphates. The optimized process uses a bench-stable succinimide-based Pd precatalyst (FurCat) to promote Pd-catalyzed allylic ammonium salt generation from the allylic phosphate and the glycine aryl ester. Subsequent in situ enantioselective [2,3]-sigmatropic rearrangement catalyzed by the isothiourea benzotetramisole forms syn-α-amino acid derivatives with high diastereo- and enantioselectivity. This methodology is most effective using 4-nitrophenylglycine esters and tolerates a variety of substituted cinnamic and styrenyl allylic ethyl phosphates. The use of challenging unsymmetrical N-allyl-N-methylglycine esters is also tolerated under the catalytic relay conditions without compromising stereoselectivity.
- Spoehrle, Stéphanie S. M.,West, Thomas H.,Taylor, James E.,Slawin, Alexandra M. Z.,Smith, Andrew D.
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supporting information
p. 11895 - 11902
(2017/09/07)
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- Catalytic Anti-Markovnikov Hydroallylation of Terminal and Functionalized Internal Alkynes: Synthesis of Skipped Dienes and Trisubstituted Alkenes
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We have developed catalytic anti-Markovnikov hydroallylation of terminal and functionalized internal alkynes. In this article, we describe the development of the reaction, exploration of the substrate scope, and a study of the reaction mechanism. Synthesis of skipped dienes through the hydroallylation of terminal alkyl and aryl alkynes with simple allyl phosphates and 2-substituted allyl phosphates is described. The hydroallylation of functionalized internal alkynes leads to the formation of skipped dienes containing trisubstituted alkenes. We demonstrate that the hydroallylation of internal alkynes can be used in the regio- and diastereoselective synthesis of complex trisubstituted alkenes. A mechanism of the hydroallylation reaction is proposed, and experimental evidence is provided for the key steps of the catalytic cycle. Stoichiometric experiments demonstrate an unexpected role of lithium alkoxide in the carbon-carbon bond-forming step of the reaction. A study of the hydrocupration of internal alkynes provides new insight into the structure, stability, and reactivity of alkenyl copper intermediates, as well as insight into the source of the regioselectivity in reactions of internal alkynes.
- Mailig, Melrose,Hazra, Avijit,Armstrong, Megan K.,Lalic, Gojko
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supporting information
p. 6969 - 6977
(2017/05/31)
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- Phenyliodine(III) Bis(trifluoroacetate) Mediated Synthesis of 6-Piperidinylpurine Homo-N-nucleosides Modified with Isoxazolines or Isoxazoles
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The room temperature, 1,3-dipolar cycloaddition reactions of the nitrile oxide obtained from (6-piperidin-1-yl-9H-purin-9-yl)acetaldehyde oxime upon phenyliodine(III) bis(trifluoroacetate) treatment with excess unsaturated alcohols as solvent resulted in isoxazoline or isoxazole derivatives in almost quantitative yields. Analogous derivatives were prepared from the reactions of unsaturated phosphates. Preliminary biological tests indicated inhibition of lipid peroxidation for some of the examined compounds.
- Balalas, Thomas,Peperidou, Catherine,Hadjipavlou-Litina, Dimitra J.,Litinas, Konstantinos E.
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p. 281 - 292
(2016/01/15)
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- Metal catalyst-free substitution of allylic and propargylic phosphates with diarylmethyl anions
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Substitution of secondary allylic phosphates with the anions derived from Ar2CH2 with BuLi or LDA proceeded regioselectively and stereoselectively without a metal catalyst, affording inversion products in good yield. Similarly, propargylic phosphates gave propargylic products selectively.
- Kawashima, Hidehisa,Ogawa, Narihito,Saeki, Ryohei,Kobayashi, Yuichi
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supporting information
p. 4918 - 4921
(2016/04/10)
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- Cross-hetero-dehydrogenative coupling reaction of phosphites: A catalytic metal-free phosphorylation of amines and alcohols
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Phosphorylation of amines, alcohols, and sulfoximines are accomplished using molecular iodine as a catalyst and H2O2 as the sole oxidant under mild reaction conditions. This method provides an easy route for synthesizing a variety of phosphoramidates, phosphorus triesters and sulfoximine-derived phosphoramidates which are of biological importance.
- Dhineshkumar, Jayaraman,Prabhu, Kandikere Ramaiah
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supporting information
p. 6062 - 6065
(2014/01/06)
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- An efficient method for phosphorylation of alcohols: Preparation of porphyrin-derived phosphates
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An effective method for the phosphorylation of phenols and various alcohols including porphyrins bearing hydroxyl groups was developed. The reaction of 6,7-bis(3-hydroxypropyl)-1,3,5,8-tetramethyl-2,4-divinylporphyrin with dialkyl chlorophosphate in the presence of DABCO as both a catalyst and a proton scavenger gave the desired phosphate in 97% yield.
- Pisarek, Sabina,Bednarski, Hubert,Gryko, Dorota
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p. 2667 - 2671,5
(2012/12/12)
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- An efficient method for phosphorylation of alcohols: Preparation of porphyrin-derived phosphates
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An effective method for the phosphorylation of phenols and various alcohols including porphyrins bearing hydroxyl groups was developed. The reaction of 6,7-bis(3-hydroxypropyl)-1,3,5,8-tetramethyl-2,4-divinylporphyrin with dialkyl chlorophosphate in the presence of DABCO as both a catalyst and a proton scavenger gave the desired phosphate in 97% yield. Georg Thieme Verlag KG Stuttgart · New York.
- Pisarek, Sabina,Bednarski, Hubert,Gryko, Dorota
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p. 2667 - 2671
(2013/01/15)
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- Palladium-catalyzed cross-couplings of allylic phosphates
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A range of palladium-catalyzed cross-coupling reactions can be performed using allylic phosphates as electrophiles. Both conventional heating and microwave irradiation can be used.
- Maslak, Veselin,Tokic-Vujosevic, Zorana,Saicic, Radomir N.
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supporting information; experimental part
p. 1858 - 1860
(2009/07/19)
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- Phosphorylation of alcohols with N-phosphoryl oxazolidinones employing copper(II) triflate catalysis
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(Chemical Equation Presented) Phosphoryl transfer from N-phosphoryl 5,5-diphenyl oxazolidinone is efficiently catalyzed by copper(II) triflate. The utility of this method has been demonstrated in the phosphorylation of representative primary, secondary, tertiary, phenolic, and allylic alcohols. These reaction conditions are significantly milder than employing alkoxides and allow the phosphorylation of biologically relevant molecules.
- Jones, Simon,Smanmoo, Chaiwat
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p. 3271 - 3274
(2007/10/03)
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- N-Phosphoryl oxazolidinones as effective phosphorylating agents
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A number of N-phosphoryl oxazolidinones have been prepared and evaluated, the best being 5,5-diphenyl oxazolidinones, the utility of which was demonstrated in the phosphorylation of a number of representative primary, secondary, tertiary, and phenolic alcohols.
- Jones, Simon,Smanmoo, Chaiwat
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p. 1585 - 1588
(2007/10/03)
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- A simple, general and improved procedure for phosphorylation of alcohols catalyzed by indium(III) chloride
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A general and efficient procedure has been developed for the preparation of dialkyl phosphate esters by indium(III) chloride catalyzed phosphoryl transfer from diethyl and diphenyl chlorophosphate to a variety of alcohols and phenols in THF in presence of triethylamine.
- Ranu, Brindaban C.,Das, Arijit
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p. 1063 - 1064
(2007/10/03)
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- Allyl- and propargylchromium reagents generated by a chromium(III) ate-type reagent as a reductant and their reactions with electrophiles
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A chromium ate-type reagent 'Bu5CrLi2' reacts with allylic and propargylic phosphates to generate the corresponding allyl- and propargylchromium (propargyl = prop-2-ynyl) reagents which further react with a variety of electrophiles such as aldehydes, ketones, imines, and isocyanates to afford the corresponding adducts in high yields.
- Hojo,Sakuragi,Okabe,Hosomi
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p. 357 - 358
(2007/10/03)
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- A new polymeric flame retardant additive for vinyl polymers
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Diethyl allyl phosphate (DEAP) monomer has been synthesized, and characterized, using 1H NMR and direct ionization mass spectrometric (DI-MS) techniques. It was free-radically polymerized to yield the poly(diethyl allyl phosphate) (PDEAP). The direct pyrolysis-mass spectrometric (DP-MS) analysis of the PDEAP revealed that it undergoes thermal degradation to yield mainly the monomer. Utility of PDEAP as a potent flame-retardant additive in polystyrene (PS) and poly(methyl methacrylate) (PMMA) has also been established.
- Sundarrajan,Kishore,Ganesh
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- Direct Transformation of Trialkyl Phosphates into Organolithium Compounds by a DTBB-Catalysed Lithiation
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The reaction of different alkylic or phenylic phosphates 1 with an excess of lithium powder and a catalytic amount of DTBB (5 mol percent) in the presence of an electrophile -Barbier-type reaction conditions- in THF at -30 deg C leads to the formation of the expected products 2, resulting from the reaction of the in situ generated organolithium compound with the corresponding electrophile.
- Guijarro, David,Mancheno, Balbino,Yus, Miguel
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p. 8551 - 8558
(2007/10/02)
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- Direct Esterification of Phosphates with Various Halides and its Application to Synthesis of cAMP Alkyl Triesters
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Esterification of phosphates with various halides, including acid chlorides, phosphoryl trichloride and chloride, was achieved in 57-99percent isolated yield using silver(I) oxide.The reaction was successfully applied to the preparation of phosphate triesters sensitive to acids and bases. cAMP benzyl esters were also prepared by this method.
- Furuta, Toshiaki,Torigai, Hiromi,Osawa, Tomoko,Iwamura, Michiko
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p. 3139 - 3142
(2007/10/02)
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- The Selective Dealkylation of Mixed Esters of Phosphoric Acid and Phenylphosphonic Acid Using Cation Exchange Resin
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Cation exchange resin (SO3H) is a highly selective dealkylation reagent for mixed esters of phosphorus oxyacids bearing primary and secondary alkyl groups.The desired products which were produced by dealkylation of the secondary alkyl group were obtained in high yields under anhydrous and mild conditions.Keywords - dealkylation; cation exchange resin; carbonium ion; phosphorus oxyacid ester; trialkyl phosphate; dialkyl phenylphosphonate; p-toluenesulfonic acid
- Nitta, Yoshihiro,Arakawa, Yasushi
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p. 3121 - 3129
(2007/10/02)
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