钒酸根阴离子催化叔丁基过氧化氢进行烷烃氢过氧化反应的动力学及机理

Kinetics and mechanism of alkane hydroperoxidation with tert-butyl hydroperoxide catalysed by a vanadate anion.

作者信息

Shul'pin Georgiy B, Kozlov Yuriy N

机构信息

Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina, dom 4, Moscow 119991, Russia.

出版信息

Org Biomol Chem. 2003 Jul 7;1(13):2303-6. doi: 10.1039/b302228e.

DOI:10.1039/b302228e

PMID:12945701

Abstract

tert-Butyl hydroperoxide oxidizes alkanes in acetonitrile at 60 degrees C if the soluble vanadium(v) salt, n-Bu4NVO3, is used as a catalyst. Alkyl hydroperoxides are formed as main products which decompose during the course of the reaction to produce the more stable corresponding alcohols and ketones. Turnover numbers (ie. numbers of moles of products per one mole of a catalyst) attained 250. The kinetics and selectivity of the reaction have been studied. The mechanism proposed involves the formation of a complex between the V(V) species and t-BuOOH (K5 was estimated to be 5 dm3 mol(-1)) followed by decomposition of this complex (k6 = 0.2 s(-1)). The generated V(IV) species reacts with another t-BuOOH molecule to produce an active t-BuO* radical which attacks the hydrocarbon.

摘要

如果使用可溶性钒（Ⅴ）盐四丁基钒酸铵（n-Bu4NVO3）作为催化剂，叔丁基过氧化氢在60℃的乙腈中可氧化烷烃。烷基过氧化氢是主要产物，在反应过程中会分解生成更稳定的相应醇类和酮类。周转数（即每摩尔催化剂生成产物的摩尔数）达到了250。对该反应的动力学和选择性进行了研究。提出的机理涉及V（Ⅴ）物种与叔丁基过氧化氢之间形成络合物（估计K5为5 dm3 mol⁻¹），随后该络合物分解（k6 = 0.2 s⁻¹）。生成的V（Ⅳ）物种与另一个叔丁基过氧化氢分子反应生成活性叔丁氧基（t-BuO*）自由基，该自由基进攻烃类。