Journal of the Chemical Society, Dalton Transactions p. 1283 - 1288 (1981)
Update date:2022-07-29
Topics:
Goldschmidt, Jacob M. E.
Goldstein, Rebecca
With the aim of elucidating the mechanistic origins of trans preference as observed in the amination reactions of chlorocyclophosphanzenes, a kinetic study of the reactions of pentachloro(dimethylamino)cyclotriphosphazene, N3P3Cl5(NMe2), with NMe2H in tetrahydrofuran produce cis-and trans-N3P3Cl4(NMe2)2 has been undertaken.Gas chromatograpic analysis was employed to follow the changes in the concentrations of the components of the product mixture with time, from which rate constants for both cis and the trans reactions at various temperatures, as well as the values of the enthalpies and the entropies of activation of both reactions, have been evaluated.The data show that the trans prefence is due solely to the fact that ΔS(exit)trans>ΔS(exit)cis.To explain the origin of trans preference the operation of modified substituent-solvating effect is postulated, according to which the substituent, after protonation, functions as a neighbouring group that by intramolecular acid catalysis facilitates departure of the chloride ion.This mechanism specifically favours the formation of the trans isomer as for steric reasons it cannot aid the formation of the cis isomer.
View MoreJinzhou Jiutai Pharmaceutical Co.,Ltd
Contact:+86-0416-5179890
Address:No.41, Taianli, Taihe District, Jinzhou, Liaoning
website:https://www.yurisolar.com/en
Contact:86--18092602675
Address:No. 560, East Hangtian Road, Xi'an, China
Nanjing Fubang Chemical Co.,Ltd
Contact:+86-25-83179199
Address:5F,Tianzheng international plaza,No399 Zhongyang Road ,Nanjing China
Contact:+86 021-51698675
Address:1701, Jielong Plaza, No.618 Pingliang Rd, ShangHai,China
Antaeus Bio-technology Co., LTD(expird)
Contact:021-31252569
Address:shanghai pudong
Doi:10.1039/DT9940002515
(1994)Doi:10.1021/ja00149a011
(1995)Doi:10.1016/j.tetlet.2014.03.004
(2014)Doi:10.1055/s-1994-25545
(1994)Doi:10.1016/j.tet.2014.03.037
(2014)Doi:10.1039/c4cc00857j
(2014)
