中文摘要：

卤代苯与酚类化合物反应制取二芳基醚是现代有机合成中的一个重要反应.传统的二苯醚合成方法是铜催化卤代苯与酚类化合物的Ullmann型C–O偶联反应,但是这种方法需要苛刻的反应条件.后来,人们发现了Pd(0)和Cu(I)基催化剂,但是前者成本较高,且需要使用昂贵的配体,因此其应用受到了限制,而铜作为一种成本较低的催化剂受到了越来越多的关注.铜催化剂可以分为均相和非均相两大类.均相铜催化剂使用的是铜盐,并且需要加入配体,成本较高,且不易分离和循环利用.非均相铜催化剂研究较多的是CuO,Cu2O及Cu纳米颗粒,其中Cu2O纳米颗粒催化剂对Ullmann型C–O偶联反应具有很高的催化活性,但是它在潮湿的空气中容易被氧化,因此需要寻找一种合适的载体防止Cu2O纳米颗粒被氧化.

英文摘要：

A Cu2O/SiC heterogeneous catalyst was prepared via a two‐step liquid‐phase method using diethyleneglycol as both the solvent and the reducing agent.The catalyst was characterized using X‐raydiffraction,X‐ray photoelectron spectroscopy,scanning electron microscopy(SEM),transmissionelectron microscopy(TEM),and H2temperature‐programmed reduction.All the results indicatethat Cu is present on the SiC support primarily as Cu2O.The SEM and TEM results show that cubicCu2O nanoparticles are uniformly dispersed on theβ‐SiC surface.The reaction conditions,namelythe temperature,reaction time,and amounts of base and catalyst used,for the Ullmann‐type C–Ocross‐coupling reaction were optimized.A model reaction was performed using iodobenzene(14.0mmol)and phenol(14.0mmol)with Cu2O/SiC(5wt%Cu)as the catalyst,Cs2CO3(1.0equiv.)as thebase,and tetrahydrofuran as the solvent at150°C for3h;a yield of97%was obtained and theturnover frequency(TOF)was1136h?1.The Cu2O/SiC catalyst has a broad substrate scope and canbe used in Ullmann‐type C–O cross‐coupling reactions of aryl halides and phenols bearing a varietyof different substituents.The catalyst also showed high activity in the Ullmann‐type C–Scross‐coupling of thiophenol with iodobenzene and substituted iodobenzenes;a TOF of1186h?1was achieved.The recyclability of the Cu2O/SiC catalyst in the O‐arylation of phenol with iodobenzenewas investigated under the optimum conditions.The yield decreased from97%to64%afterfive cycles.The main reason for the decrease in the catalyst activity is loss of the active component,i.e.,Cu2O.