双胺基双酚铜配合物催化甲苯氧化合成苯甲酸

Catalytic Oxidation of Toluene to Benzoic Acid over Diamino-Bis(phenolate)Copper Complex

通过将四齿双胺基双酚配体与铜盐发生配位反应制备得到一种结构新颖的双胺基双酚铜配合物。将所得配合物作为均相催化剂应用于氧气存在条件下、以N-羟基邻苯二甲酰亚胺为助催化剂的甲苯氧化合成苯甲酸反应中。结果表明,该催化剂在温和的条件下实现了甲苯分子中C─H键的活化和氧化,且高选择性得到了产物苯甲酸。系统考察了催化剂用量、助催化剂用量、反应温度、氧气压力和反应时间等因素对催化性能的影响。在最佳反应条件下,甲苯转化率为51.8%,苯甲酸选择性可达91.4%。

A novel structure of diamino-bis(phenolate)copper complex was prepared based on coordination reaction of a quadridentate diamino-bis(phenolate)ligand with copper salt.The obtained complex compound was then employed as homogeneous catalyst for the synthesis of benzoic acid from toluene in the presence of molecular oxygen by using N-hydroxyphthalimide as a co-catalyst.The results showed that this catalyst achieved the activation and oxidation of C-H bonds in toluene molecules under mild conditions,and the product benzoic acid was obtained with high selectivity.The effects of reaction parameters including catalyst loading,co-catalyst dosage,reaction temperature,O 2 pressure and reaction time on catalytic performance were investigated systematically.Under the optimal reaction conditions,good conversion of toluene(51.8%)and selectivity to benzoic acid(91.4%)were obtained.