- Metal-free synthesis of biarenes via photoextrusion in di(tri)aryl phosphates
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A metal-free route for the synthesis of biarenes has been developed. The approach is based on the photoextrusion of a phosphate moiety occurring upon irradiation of biaryl- A nd triaryl phosphates. The reaction involves an exciplex as the intermediate and it is especially suitable for the preparation of electron-rich biarenes.
- Qrareya, Hisham,Meazza, Lorenzo,Protti, Stefano,Fagnoni, Maurizio
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supporting information
p. 3008 - 3014
(2021/01/18)
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- Zinc-catalyzed transformation of diarylphosphoryl azides to diarylphosphate esters and amides
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We have developed a facile and efficient procedure for the synthesis of diarylphosphate esters and amides. Using Zn(acac)2 as the catalyst, the reaction of diarylphosphoryl azides with aliphatic alcohols and phenols through an unusual P?N bond cleavage provided a number of diarylphosphate esters in good yields (22 examples, up to 94%). Additionally, various diarylphosphate amides were obtained from the corresponding amines in excellent yields as well (8 examples, up to 96%).
- Ying, Jun,Gao, Qian,Wu, Xiao-Feng
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p. 1540 - 1543
(2020/04/15)
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- Direct aerobic oxidative esterification and arylation of P(O)-OH compounds with alcohols and diaryliodonium triflates
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Copper-catalyzed aerobic oxidative esterification of P(O)-OH compounds is achieved using alcohols as efficient esterification reagents, giving the expected products with good to moderate yields. Furthermore, it is shown that the arylation of P(O)-OH compounds proceeds efficiently to produce the corresponding products via the treatment of diaryliodonium triflates under mild reaction conditions. It is a simple way to produce a broad spectrum of functionalized phosphinates, phosphonates, and phosphates from basic starting materials with good to excellent yields. The protocol is convenient for practical application. A plausible mechanism has been proposed for the reaction.
- Xiong, Biquan,Feng, Xiaofeng,Zhu, Longzhi,Chen, Tieqiao,Zhou, Yongbo,Au, Chak-Tong,Yin, Shuang-Feng
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p. 537 - 543
(2015/04/14)
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- An improved method for Lewis acid catalyzed phosphoryl transfer with Ti(t-BuO)4
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Several inorganic esters have been evaluated as phosphoryl transfer catalysts. Of these, Ti(t-BuO)4 was found to be the most effective catalyst giving excellent yields of the desired phosphate esters. The loading of the catalyst could be reduced to a little as 5 mol % for a majority of substrates with no loss in the yield of product. This methodology is significantly more versatile than using TiCl4 and is suitable for the phosphorylation of more complex carbohydrates and molecules of biological interest.
- Jones, Simon,Selitsianos, Dimitrios,Thompson, Kate J.,Toms, Steven M.
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p. 5211 - 5216
(2007/10/03)
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- A simple and effective method for phosphoryl transfer using TiCl4 catalysis
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(graph presented) A number of Lewis acids have been evaluated as catalysts for the phosphoryl transfer, the most efficient being TiCl4. Application of this methodology to the phosphorylation of a number of representative target alcohols is presented.
- Jones, Simon,Selitsianos, Dimitrios
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p. 3671 - 3673
(2007/10/03)
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- Potential mechanism-based tyrosine kinase inhibitors. Part 1. Phosphorylation chemistry of pyridine N-oxides
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Phosphorylated derivatives of 4-picoline N-oxide have been observed on treatment with both phosphorylating and phosphitylating agents.These intermediates were trapped by external nucleophiles.Propane-1-thiol reacted preferentially at carbon to yield a propylsulfanylpyridine whereas propylamine reacted preferentially at phosphorus.This chemistry carries implications for the design of mechanism-based tyrosine kinase inhibitors.
- Andrews, David M.,Page, Timothy C. M.,Peach, Josephine M.,Pratt, Andrew J.
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p. 1045 - 1048
(2007/10/02)
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- Dependence of Transition-state Structure on Nucleophile in the Reaction of Aryl Oxide Anions with Aryl Diphenylphosphate Esters
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Second-order rate constants have been measured for reaction of aryl oxide anions with substituted phenyl diphenylphosphate esters in aqueous media at 25 deg C.The rate constants obey good Broensted type correlations with the pKa of either the leaving group or nucleophile.Both βnuc and βlg values vary substantially with basicity of leaving group and nucleophile, respectively, providing evidence for coupling between bond fission and formation.Attack of phenolate ions on 2,4-dinitrophenyl diphenylphosphate has a βnuc value of 0.12 giving a Kreevoy's tightness parameter value, τ, of 0.18 which is consistent with an 'exploded' transition state for the identity reaction involving 2,4-dinitrophenolate ion as the nucleophile.Transfer of the diphenylphosphinoyl group between 2,4-dinitrophenolate ion nucleophiles has a τ value of 0.28, consistent with an 'exploded' transition state for this reaction also.The identity reaction involving transfer of the diphenylphosphoryl group between phenolates ions has a τ value of 1.20, indicating an almost synchronous process.The data for transfer of the diphenylphosphinoyl and diethylphosphoryl groups between phenolate ion nucleophiles indicates that the identity reaction for the parent phenol has an almost synchronous mechanism for the former phosphinoyl species (τ = 0.92) whereas the latter (τ = 1.45) is almost associative.
- Ba-Saif, Salem A.,Waring, Mark A.,Williams, Andrew
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p. 1653 - 1659
(2007/10/02)
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