Alkane oxidation with air catalyzed by lipophilic N-hydroxyphthalimides without any solvent.
Alkane oxidation with air catalyzed by lipophilic N-hydroxyphthalimides without any solvent.
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DOI：
10.1021/jo0158276
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发表时间：
2001-10
期刊：
影响因子：
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通讯作者：
N. Sawatari;T. Yokota;S. Sakaguchi;Y. Ishii
中科院分区：
文献类型：
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作者：
N. Sawatari;T. Yokota;S. Sakaguchi;Y. Ishii
尽管在用分子氧氧化饱和烃方面已经取得了重大进展，但是开发用于烃的催化官能化的有效和选择性方法仍然是氧化化学中的主要挑战。特别地，从经济和环境两方面来看，用分子氧选择性氧化烷烃为含氧化合物如醇、酮和羧酸是非常重要的工业方法。1传统的烷烃分子氧氧化，即自氧化，通常条件相对苛刻，转化率和选择性有限。2例如，环己烷自动氧化成环己酮和环己醇的混合物（K/A油）现在在全世界范围内使用可溶性钴催化剂以工业规模进行。该方法的缺点是氧化必须在环己烷的3-6%转化率下操作以保持对K/A油的较高选择性（75-80%）。在20世纪40年代，杜邦公司首次将该工艺工业化，目的是从K/A油中生产己二酸。3.尽管人们已经做了很多努力来开发一种有效的环己烷与分子氧的氧化系统，但目前采用的是杜邦方法，没有进行重大修改。近年来，我们发展了一种以N-羟基邻苯二甲酰亚胺（NHPI）为催化剂，在温和条件下进行烷烃分子氧氧化的新方法。4.在常压、氧气存在下、100 ℃、乙酸中，以NHPI和Mn（Ac）_3为复合催化剂，环己烷转化为己二酸，具有较高的转化率（70%）和选择性（70%）。5我们实验室以前的工作集中在烃类的有氧氧化必须在适当的溶剂如乙酸或苯甲腈中进行，因为NHPI很难溶解在非极性溶剂如烃类中。因此，令人感兴趣的是开发容易溶解于烃如环己烷中的NHPI衍生物。如果可以制备这样的催化剂，则烷烃的有氧氧化可以在没有任何溶剂的情况下进行。本研究的重点是制备NHPI衍生物不需要使用溶剂的烷烃与分子氧在温和的条件下氧化。
Although there have been major advances in the oxidation of saturated hydrocarbons with molecular oxygen, the development of effective and selective methods for the catalytic functionalization of hydrocarbons still remains a major challenge in oxidation chemistry. In particular, selective oxidation of alkanes with dioxygen to oxygen-containing compounds such as alcohols, ketones, and carboxylic acids is a very important industrial process from both economical and environmental aspects. 1 Traditional alkane oxidation with dioxygen, which is referred to as autoxidation, often suffers from relatively harsh conditions and limited conversion and selectivity. 2 For instance, autoxidation of cyclohexane to a mixture of cyclohexanone and cyclohexanol (K/A oil) is now carried out using a soluble cobalt catalyst in industrial scale worldwide. The drawback of this process is that the oxidation must be operated in 3-6% conversion of cyclohexane to maintain higher selectivity (75-80%) to the K/A oil. In the 1940s, DuPont first industrialized this process for the purpose of the production of adipic acid from the K/A oil. 3 Although much effort has been made to develop an effective oxidation system of cyclohexane with molecular oxygen, the DuPont process is currently employed without major modification. Recently, we have developed a novel method for alkane oxidation with dioxygen using the N-hydroxyphthalimide (NHPI) as a catalyst under mild conditions. 4 Thus, cyclohexane can be converted into adipic acid in higher conversion (70%) and selectivity (70%) by a combined catalyst of NHPI with Mn (OAc) 3 under normal pressure of dioxygen in acetic acid at 100 C. 5 Previous work from our laboratory focused on the aerobic oxidations of hydrocarbons must be carried out in an appropriate solvent such as acetic acid or benzonitrile, since NHPI is difficult to dissolve in nonpolar solvents such as hydrocarbons. Therefore, it is interesting to develop NHPI derivatives that easily dissolve in hydrocarbons such as cyclohexane. If such a catalyst can be prepared, the aerobic oxidation of alkanes can proceed without any solvent. This study is focused on the preparation of NHPI derivatives not requiring the use of solvents for the oxidation of alkanes with dioxygen under mild conditions.