Journal of the American Chemical Society p. 628 - 634 (1981)
Update date:2022-08-29
Topics:
Emly, Mark
Leussing, Daniel L.
The hydration/dehydration and tautomerization rates of oxalacetate are subject to acid and base catalysis.H2O and OH- are much more effective for the former process than for the latter, but the opposite holds for tertiary amine catalysis.In buffers comprised of oxyanion bases or unsaturated amines, dehydration is significantly faster than tautomerization and remains so as the buffer concentration is varied.In dilute tertiary amine buffers dehydration rates are also faster, but as the buffer concentration increases, tautomerization rates increase rapidly and eventually surpass those for hydration/dehydration.It is this rate crossover which led earlier workers (ref 9) to propose a carbinolamine mechanism for a tertiary amine-catalyzed tautomerization.After the rate crossover is taken into account, enolization is found to show linear rate-buffer concentration behavior with tertiary amines, vitiating the prime evidence cited for the carbinolamine mechanism.However, tertiary amine catalysis likely operates differently in the tautomerization and dehydration reactions.
View MoreContact:021-50278900
Address:No.6,Room 201 ,Lane 299,bisheng road ,shanghai ,china
Xuzhou Tianrun Chemical Co.,Ltd
website:http://www.tianrunchem.cn
Contact:86-516-83832636
Address:fuxing road
Contact:+86-134-5286-9121
Address:Add: Wing Tuck Commercial Centre, 177-183 Wing Lok Street, Hong Kong,
SHAANXI FUJIE PHARMACEUTICAL CO.,LTD
website:http://www.fujiepharm.com
Contact:+86-29-63650906
Address:Yuanqu Yi Road, Qinghe Food Industrial Park, Sanyuan County, Shaanxi Province, China
Hebei Lead Bio-Chemicals Co., Ltd.
website:http://www.ldbiochem.com
Contact:+86-311-87826503
Address:481, Heping West Road, Shijiazhuang,China
Doi:10.1021/ja01588a015
(1956)Doi:10.1021/ja00165a057
(1990)Doi:10.1246/cl.1987.1843
(1987)Doi:10.1021/ol9028918
(2010)Doi:10.1016/0031-9422(95)00154-Y
(1995)Doi:10.1016/j.apcata.2012.03.002
(2012)