水溶性Salen促进CuBr催化叔丁基氢过氧化物氧化水中芳烃侧链α位C-H键

Water soluble Salen promoted CuBr catalyzed tert-butyl hydrogen peroxide to oxideα-C-H bond of alkylbenzene in water

本文报道一种水溶性Salen(N,N’-双(亚甲基-2-羟基-5-苯磺酸钠)缩-N,N’-二甲基乙二胺)促进CuBr催化TBHP水溶液氧化侧链芳烃α-位C-H键的氧化反应。以乙基苯为底物,考察了不同金属盐、以及相转移催化剂对催化氧化反应的影响。发现以十二烷基硫酸钠为相转移催化剂时,室温反应2 h,RuCl 3和CuI分别能获得80%和79%的乙基苯转化率,CuBr也能得到70%的乙基苯转化率以及94%生成苯乙酮的选择性。考虑到催化剂的使用成本,选取CuBr为催化剂,在相同条件下,考察了其它侧链芳烃的氧化,都获得了中等到好的转化率和大于90%的芳基酮的选择性。

A water soluble Salen(N,N’-bis[(5-sosium sulfonate-2-hydroxy)benzyl]N,N’-dimethyl-ethane-diamine)was used for promoting CuBr catalyzed tert-butyl hydrogen peroxide(TBHP)aqueous solution to oxidize alkylbenzene.The influences of different transition metal halidesand phase transfer catalyst on the oxidation of ethylbenzene were investigated.It was found that the oxidation was carried out for 2 h at room temperature with sodium dodecyl sulfate as phase transfer catalyst,RuCl 3 and CuI separately obtained 80%and 79%of ethylbenzene conversion,and CuBr also obtained 70%of ethylbenzene conversion with 94%selectivity of acetophenone.Considered the cost of catalyst,CuBr was used as catalyst for investigating the oxidation of other alkylbenzene.Under the same reaction condition,moderate to good conversions of substrate were obtained,which were with more than 90%selectivity of aryl-ketone.