- Transformation of Carbonyl Compounds into Homologous Alkynes under Neutral Conditions: Fragmentation of Tetrazoles Derived from Cyanophosphates
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Cyanophosphates (CPs) can be easily prepared from either ketones or aldehydes, and their reaction with NaN3-Et3N·HCl results in the formation of azidotetrazoles. Under microwave irradiation, successive fragmentation of the azidotetrazoles generates alkylidene carbenes that undergo [1,2]-rearrangement and are transformed into homologous alkynes. Treatment of ketone-derived CPs with TMSN3 and Bu2SnO as catalyst in toluene at reflux directly yields the corresponding internal alkynes, whereas the reaction of aldehyde-derived CPs with NaN3-Et3N·HCl in THF at reflux or TMSN3-Bu2SnO (cat.) in toluene at reflux provides homologous terminal alkynes in good yields. These reactions take place under neutral conditions and can be successfully extended to obtain alkynes that are not usually accessible from the corresponding carbonyl compounds by the Ohira-Bestmann or Shioiri procedures, which require basic conditions.
- Yoneyama, Hiroki,Numata, Masahiro,Uemura, Kenji,Usami, Yoshihide,Harusawa, Shinya
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p. 5538 - 5556
(2017/06/07)
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- Cyano Phosphate: An Efficient Intermediate for the Chemoselective Conversion of Carbonyl Compounds to Nitriles
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Cyanohydrin diethyl phosphates, readily obtained from various ketones and aldehydes by reaction with diethyl phosphorocyanidate and lithium cyanide, reacted chemoselectively with samarium(II) iodide in THF to give the corresponding nitriles in excellent yields.This method was also found applicable to α,β-unsaturated carbonyl compounds via cyano phosphates to give β,γ-unsaturated nitriles, not obtainable by standard methods, without isomerization of the double bonds.
- Yoneda, Ryuji,Harusawa, Shinya,Kurihara, Takushi
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p. 1827 - 1832
(2007/10/02)
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- CYANOPHOSPHATE: AN EFFICIENT INTERMEDIATE FOR CONVERSION OF CARBONYL COMPOUNDS TO NITRILES
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A novel and high yield conversion of saturated or unsaturated carbonyl compounds to nitriles via cyanophosphates by samarium diiodide in the presence of tert-butanol is described.
- Yoneda, Ryuji,Harusawa, Shinya,Kurihara, Takushi
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p. 3681 - 3684
(2007/10/02)
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- A NEW SYNTHESIS OF SOME NON-STEROIDAL ANTI-INFLAMMATORY AGENTS VIA CYANOPHOSPHATES
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A simple and convenient procedure for the syntheses of some non-steroidal anti-inflammatory agents, ibuprofen, rac-naproxen, clidanac and loxoprofen, is described.
- Hurusawa, Shinya,Nakamura, Shuji,Yagi, Sayoko,Kurihara, Takushi,Hamada, Yasumasa,Shioiri, Takayuki
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p. 1365 - 1372
(2007/10/02)
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- CYANOPHOSPHORYLATION OF KETONES AND ALDEHYDES USING DIETHYL PHOSPHOROCYANIDATE (DEPC)
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A novel one-pot and high-yield cyanophosphorylation of carbony compounds is achieved by treatment of ketones or aldehydes with diethyl phosphorocyanidate (DEPC) in the presence of a catalytic amount of lithium diisopropylamide in tetrahydrofuran.KEYWORDS
- Harusawa, Shinya,Yoneda, Ryuji,Kurihara, Takushi,Hamada, Yasumasa,Shioiri, Takayuki
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p. 2932 - 2935
(2007/10/02)
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