Stepwise base-promoted elimination of hydrochloric acid via hydrogen-bonded carbanions studied by reaction branching and extreme deuterium isotope effects. Parallel carbocationic and carbanionic reactions
Etude de la reaction des (chloro-1'methyl-1'ethyl)-1 ou -3 indene avec la pyridine dans le methanol
反应练习曲 des (chloro-1'methyl-1'ethyl)-1 ou -3 indene avec la pyridine dans le 甲醇
Intra- and inter-molecular hydron abstraction from allylic carbocation intermediates in aqueous solvent. Observation of a substantial deuterium isotope effect for 1,4-elimination of acetic acid from one of the ion-pair intermediates
作者:Alf Thibblin
DOI:10.1039/p29860000321
日期:——
for production of (4). The kinetic deuterium isotope effect on hydron abstraction from the intermediate with acetate anion to form the olefin (3), (kH/kD) is 3.0 ± 0.4. The corresponding intramolecular elimination of aceticacidfrom the contact ion pair formed from 3-(2-acetoxypropan-2-yl)indene (1-OAc) to yield (3) shows a substantial isotope effect, kH/kD= 5.2 ± 1.0. The allylic isomer 2-acetoxy-1
烯丙型碳正离子中间体,由3-(2-氯丙-2-基)茚(形成1 -Cl),并从(1,1- 2 ħ 2) - (1 35 -Cl)在75体积%的水-乙腈° C与溶剂水迅速反应,生成烯丙基醇,但也可通过一般的碱进行水合夺氢,生成1-异亚丙基茚(3)和3-异丙烯基茚(4)。发现用取代的乙酸根阴离子测量的布朗斯台德参数很小,对于(3)的形成,β为0.16,对于(4)的产生,为0.14 。氘的动力学同位素对中间体与乙酸根阴离子形成烯烃(3)的氢吸收的影响。),(k H / k D)为3.0±0.4。从3-(2-乙酰氧基丙烷-2-基)茚(1- OAc)形成的接触离子对中分子内乙酸的相应消除,产生(3),显示出相当大的同位素效应,k H / k D = 5.2± 1.0。烯丙基异构体2-乙酰氧基-1-异亚丙基(2 - OAc)产生接触离子对,其反应产生具有相当小的同位素效应的(3),k H / k D= 2
Thibblin, Alf, Journal of the Chemical Society. Perkin transactions II, 1986, p. 313 - 320
作者:Thibblin, Alf
DOI:——
日期:——
BERGAMASCO R.; PORTER Q. N., AUSTRAL. J. CHEM. <AJCH-AS>, 1977, 30, NO 5, 1051-1059
作者:BERGAMASCO R.、 PORTER Q. N.
DOI:——
日期:——
BERGAMASCO R.; PORTER Q. N., AUSTRAL. J. CHEM. <AJCH-AS>, 1977, 30, NO 5, 1061-1071