5-亚苄基-1,3-二甲基巴比妥酸和硫代巴比妥酸的亲电性

Electrophilicity of 5-benzylidene-1,3-dimethylbarbituric and -thiobarbituric acids.

作者信息

Seeliger Florian, Berger Stefan T A, Remennikov Grygoriy Y, Polborn Kurt, Mayr Herbert

机构信息

Department Chemie und Biochemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, 81377, München, Germany.

出版信息

J Org Chem. 2007 Nov 23;72(24):9170-80. doi: 10.1021/jo071273g. Epub 2007 Oct 27.

DOI:10.1021/jo071273g

PMID:17963402

Abstract

The kinetics of reactions of acceptor-stabilized carbanions 2a-m with benzylidenebarbituric and -thiobarbituric acids 1a-e has been determined in a dimethyl sulfoxide solution at 20 degrees C. Second-order rate constants were employed to determine the electrophilicity parameters E of the benzylidenebarbituric and -thiobarbituric acids 1a-e according to the correlation equation log k(20 degrees C) = s(N + E). With E parameters in the range of -10.4 to -13.9, the electrophilicities of 1a-e are comparable to those of analogously substituted benzylidenemalononitriles.

摘要

在20℃的二甲亚砜溶液中，已测定了受体稳定的碳负离子2a - m与亚苄基巴比妥酸和亚苄基硫代巴比妥酸1a - e反应的动力学。根据相关方程log k(20℃)= s(N + E)，采用二级速率常数来确定亚苄基巴比妥酸和亚苄基硫代巴比妥酸1a - e的亲电参数E。E参数在-10.4至-13.9范围内，1a - e的亲电性与类似取代的亚苄基丙二腈相当。