α-Seleno arsonium ylides 5 have been synthesized through the reaetion of α- unfunctionalized arsonium ylides 4 with almost equimolar phenylselenenyl iodide 2.
Phosphonium or arsonium salt 1 can undergo the tandem reaction of deprotonation -oxidation-Wittig reaction with alcohol 2 in the presence of sodium hydroxide and manganese dioxide, which affords a general simplified m...Phosphonium or arsonium salt 1 can undergo the tandem reaction of deprotonation -oxidation-Wittig reaction with alcohol 2 in the presence of sodium hydroxide and manganese dioxide, which affords a general simplified method for the stereoselective synthesis of (E)- a, b-unsaturated esters 3.展开更多
We synthesized a-seleno substituted semistabilized arsoniurn ylide 3 by the transylida-tion reaction and found that it could undergo Wittig reaction smoothly as a new method for synthe-sizing vinyl selenides.
The fluorine-containing trans-l,2-cyclopropane derivatives 4ba--4dd were synthesized from the fluorine-containing electron-deficient alkenes 3a--3d with semistabilized arsonium ylides 2b--2d, in biphasic system of dic...The fluorine-containing trans-l,2-cyclopropane derivatives 4ba--4dd were synthesized from the fluorine-containing electron-deficient alkenes 3a--3d with semistabilized arsonium ylides 2b--2d, in biphasic system of dichloromethane-50% aqueous sodium hydroxide, generated in situ from the corresponding arsonium salts 1b-1d at room temperature in good yields with high stereoselectivity. The structure of fluorine-containing trans-1,2-cyclopropane derivatives were also studied.展开更多
Trans-2,3-dihydrofuran derivatives 3 or 4 substituted with a sulfonyl group were prepared with high chemoselectivity and good yields by [1＋4]-addition reaction of α,β-unsaturated ketones 1 with arsonium bromide 2 i...Trans-2,3-dihydrofuran derivatives 3 or 4 substituted with a sulfonyl group were prepared with high chemoselectivity and good yields by [1＋4]-addition reaction of α,β-unsaturated ketones 1 with arsonium bromide 2 in CH2Cl2 in the presence of potassium carbonate at room temperature.The structures of the products were characterized by IR,MS,^1H NMR,elemental analysis and single crystal X-ray diffraction analysis.A mechanism for the formation of products was also proposed.展开更多
The title compounds 6a—6f were prepared with high yield via intramolecular Wittig reaction of methyl 3-perfluoroalkyl-6-perfluoroacyl-2-triphenylphosphoranylidenehex-3,5-dienoates (5a—5i)which were obtained from the...The title compounds 6a—6f were prepared with high yield via intramolecular Wittig reaction of methyl 3-perfluoroalkyl-6-perfluoroacyl-2-triphenylphosphoranylidenehex-3,5-dienoates (5a—5i)which were obtained from the reaciton of 3-perfluoroacylprop-2-enylidenetriphenylphos- phoranes(3a—3c)with methyl perfluoroalkynoates(4a—4c).展开更多
On treatment of N-tosylimines (1) and 4-hydroxyl-cis-butenyl arsonium salt (5) with KOH in acetonitrile at room temperature, 2-(a-substituted N-tosylaminomethyl)-2,5-dihydrofurans (4) were obtained in moderate yields....On treatment of N-tosylimines (1) and 4-hydroxyl-cis-butenyl arsonium salt (5) with KOH in acetonitrile at room temperature, 2-(a-substituted N-tosylaminomethyl)-2,5-dihydrofurans (4) were obtained in moderate yields. The arsonium salt (5) acts formally as an equivalent of 2,5-dihydrofuran synon. A plausible mechanism was proposed for this new 5-membered cyclization reaction.展开更多
a-Phenylthio-a, b-unsaturated esters 6 were synthesized by Witting reaction of 3, which were prepared by a phenylsulfenyllation-trans-ylidation reaction.
基金National Natural Science Foundation of China!29502006
文摘α-Seleno arsonium ylides 5 have been synthesized through the reaetion of α- unfunctionalized arsonium ylides 4 with almost equimolar phenylselenenyl iodide 2.
基金We thank the National Natural Science Foundation of China for financial support of the project 29972036 and the Foundation of Educational Ministry for the Scholars Returning from Abroad. .
文摘Phosphonium or arsonium salt 1 can undergo the tandem reaction of deprotonation -oxidation-Wittig reaction with alcohol 2 in the presence of sodium hydroxide and manganese dioxide, which affords a general simplified method for the stereoselective synthesis of (E)- a, b-unsaturated esters 3.
文摘We synthesized a-seleno substituted semistabilized arsoniurn ylide 3 by the transylida-tion reaction and found that it could undergo Wittig reaction smoothly as a new method for synthe-sizing vinyl selenides.
基金Project supported by the the National Natural Science Foundation of China （Nos. 20872086 and 20872088）, and the Project of Shanghai Municipal Education Commission （Nos. 09YZ19 and J50102）.
文摘The fluorine-containing trans-l,2-cyclopropane derivatives 4ba--4dd were synthesized from the fluorine-containing electron-deficient alkenes 3a--3d with semistabilized arsonium ylides 2b--2d, in biphasic system of dichloromethane-50% aqueous sodium hydroxide, generated in situ from the corresponding arsonium salts 1b-1d at room temperature in good yields with high stereoselectivity. The structure of fluorine-containing trans-1,2-cyclopropane derivatives were also studied.
基金Supported by the National Natural Science Foundation of China（No.21272152）.
文摘Trans-2,3-dihydrofuran derivatives 3 or 4 substituted with a sulfonyl group were prepared with high chemoselectivity and good yields by [1＋4]-addition reaction of α,β-unsaturated ketones 1 with arsonium bromide 2 in CH2Cl2 in the presence of potassium carbonate at room temperature.The structures of the products were characterized by IR,MS,^1H NMR,elemental analysis and single crystal X-ray diffraction analysis.A mechanism for the formation of products was also proposed.
基金Project supported by the National Natural Science Foundation of China
文摘The title compounds 6a—6f were prepared with high yield via intramolecular Wittig reaction of methyl 3-perfluoroalkyl-6-perfluoroacyl-2-triphenylphosphoranylidenehex-3,5-dienoates (5a—5i)which were obtained from the reaciton of 3-perfluoroacylprop-2-enylidenetriphenylphos- phoranes(3a—3c)with methyl perfluoroalkynoates(4a—4c).
基金Project supported by the National Natural Science Foundation of China (No.29790127)Chinese Academy of Sciences.
文摘On treatment of N-tosylimines (1) and 4-hydroxyl-cis-butenyl arsonium salt (5) with KOH in acetonitrile at room temperature, 2-(a-substituted N-tosylaminomethyl)-2,5-dihydrofurans (4) were obtained in moderate yields. The arsonium salt (5) acts formally as an equivalent of 2,5-dihydrofuran synon. A plausible mechanism was proposed for this new 5-membered cyclization reaction.
基金Project 29502006 was supported by the National Natural Science Foundation of China.
文摘a-Phenylthio-a, b-unsaturated esters 6 were synthesized by Witting reaction of 3, which were prepared by a phenylsulfenyllation-trans-ylidation reaction.
