Simultaneous Epoxidation of Olefin and Hydroxylation of Aromatics during Water Electrolysis

烯烃的环氧化反应在当今的工业生产和有机合成中都具有极其重要的意义，因为环氧化物是最有用的合成中间体之一。大多数商业环氧化反应是间接的，多步共氧化。此外，这些工艺需要不稳定、易爆和昂贵的氧化剂，如过氧化氢或过氧化叔丁基。而苯酚也是工业中最重要的化学物质之一，它是通过多工序的库苯法生产的。因此，一步法合成环氧化物和苯酚是工业上最理想的方法。本研究的目的是在电解过程中实现烯烃的阳极环氧化和芳烃的阴极羟基化。首先，用[1-己烯，CH_2Cl_2，阳极|H_3PO_4/二氧化硅羊毛|，H_2O/He]电池对电解过程中1-己烯的环氧化进行了测试。我们发现pt -黑阳极在室温下对1-己烯的环氧化反应最活跃。该铂黑阳极在室温下对丙烯环氧化为环氧丙烷具有活性。在这个环氧化过程中，阴极产生大量的H_2。我们已经报道了在H_2-O_2燃料电池阴极反应中苯羟基化成苯酚的过程。形成苯酚最活跃的阴极是钯黑+Fe_2O_3/碳晶须。然后，我们将该阴极应用于电解池进行环氧化。采用[1-己烯，CH_2Cl_2， Pt-black阳极|H_3PO_4 aq./硅毛| pd -black +Fe_2O_3/CW阴极，benzne， O_2]电解过程中，阳极同时生成1,2-环氧己烷，阴极同时生成苯酚。

Epoxidation of olefins is extremely important both in the current industrial process and organic synthesis because epoxide is one of the most useful synthetic intermediates. Most of all commercial epoxidation reactions are indirect, multi-step co-oxidations. Moreover, these processes require a labile, explosive and expensive oxidant such as hydrogen peroxide or tert-butyl hydroperoxide. While, phenol that is also one of the most important chemical in industry, is manufactured by the Cumene process, multi process. Therefore, one-step syntheses of epoxide and phenol are most desirable process in industry.The purpose in this work is to success simultaneous epoxidation of olefin at anode and hydroxylation of aromatics at cathode during the water electrolysis. First, many anodes were tested for the epoxidation of 1-hexene during the water electrolysis by using the cell, [1-hexene, CH_2Cl_2, anode|H_3PO_4/silica wool|cathode, H_2O/He]. We found that Pt-black anode is the most active for the epoxidation of 1-hexene at room temperature. This Pt-black anode is active for the epoxidation of propylene to propylene oxide at room temperature. During this epoxidation, much H_2 is produced at cathode. We have already reported that the hydroxylation of benzene to phenol during H_2-O_2 fuel cell reactions at cathode. The most active cathode for the formation of phenol is Pd-black+Fe_2O_3/Carbon Whisker. Then, we applied this cathode to the electrolysis cell for epoxidation. We found that simultaneou formation of 1,2-epoxyhexane at anode and formation of phenol at cathode during water electrolysis using the electrolysis cell, [1-hexene, CH_2Cl_2, Pt-black anode|H_3PO_4 aq./silica wool|Pd-balck+Fe_2O_3/CW cathode, benzne, O_2].