Journal of Organic Chemistry p. 4369 - 4372 (1981)
Update date:2022-08-17
Topics:
Lewis, Edward S.
Colle, Karla S.
Several methoxyphosphonium trifluoromethanesulfonates (triflates) are characterized by the rates of methyl transfer to the 2,4-dinitrophenoxide ion.In acetone at 25 deg C, the measured second-order rate constants range from about 0.2 to about 40 M-1s-1, putting substances of this class among the most powerful methylating agents.The methylating power is confirmed by the measurement of the equilibrium extent of methylation of the counterion, the triflate ion.The Arbuzov rearrangement of trimethyl phosphite is slow with the catalyst methyl iodide but is fast enough with the cata lyst methyltrimethoxyphosphonium triflate to allow calorimetric measurement for the conversion of trimethyl phosphite to dimethyl methylphosphonate; ΔH = -24 +/- 2 kcal/mol.An earlier error in the measurement of the rate of this reaction is corrected, so that the mechanism of the methyl iodide catalyzed Arbuzov reaction of trimethyl phosphite is no longer in question; the first step is rate-determining.
View MoreHubei Onward Bio-Development Co., Ltd.
Contact:+86-718-8417012
Address:No.517,Shizhou Avenue,Enshi City,Hubei Province,China,445002
Contact:+86-15995924277
Address:WuZhongOu suzhou new south road 89
GuangZhe ANFA chemical co.,Ltd
Contact:86-579-87262335
Address:Guangzhe industrial area ,shaowu city ,Fujiang
Chongqing Changfeng Chemical Co., Ltd.
website:http://www.changfengchem.com
Contact:+86-23-67896333
Address:30th Floor, Longhu Ziduxingzuo Building A, 1st Branch,YuSong Rd., Yubei District, Chongqing, China
Contact:13357117572
Address:No.149 Shiji dadao Road.
Doi:10.1039/b823224e
(2009)Doi:10.1006/jcat.2001.3342
(2001)Doi:10.1039/c5cc06868a
(2015)Doi:10.1002/chem.200390045
(2003)Doi:10.1016/j.procbio.2019.09.014
(2019)Doi:10.1016/S0040-6031(02)00478-1
(2003)