芳烃氧化溴代反应及芳烃与炔烃的反应.pdfVIP

芳烃氧化溴代反应及芳烃与炔烃的反应 摘要 溴代芳烃是重要的有机合成中间体。除了可将其转化为有机金属化合物后再进一 步转化外，也可在过渡金属催化剂存在下直接将溴代芳烃与卤代芳烃、烯烃、末端炔 烃、胺及有机金属化合物等各类化合物发生偶联反应，因而有着广泛的应用。 传统的溴代芳烃直接制备法或是使用单质溴及其复合物、高价溴化合物等在无氧 化剂存在的条件下与芳烃发生溴代反应生成溴代芳烃，或是使用溴化物在各种外加氧 化剂存在的情况下与芳烃发生溴代反应生成溴代芳烃，往往都会产生大量废弃物，成 本也相对较高。 空气是环境友好、价格低廉的“绿色”氧化剂。在芳烃氧化溴代反应中，开发新 型催化剂以利用空气来代替大量氧化剂是个很有意义的课题。尽管先前已有少数几个 芳烃氧气氧化催化溴代反应被发现，但尚未有使用简单溴化物作溴源且于室温下进行 的芳烃空气氧化催化溴代反应报导。 基于本课题组以往的研究工作，我们成功实现了使用五水硝酸铋作催化剂，溴化 钾作溴源，利用空气为氧化剂，在室温下于三氟乙酸/乙腈溶液中进行的芳烃空气氧 化溴代反应，适用于苯甲醚和均三甲苯等多种活泼芳烃。 另外，我们还尝试了经由芳烃 C–H 键断裂的芳烃与炔烃反应，如分子内芳烃与炔 烃加成生成茚衍生物及芳烃与末端炔烃氧化偶联反应。 关键词：芳烃，氧化，溴代，功能化 第 I 页 OXIDATIVE BROMINATION OF ARENES AND REACTIONS BETWEEN ARENES AND ALKYNES ABSTRACT Bromoarenes are important intermediates in organic synthesis. For example, they can not only be transformed to organometallics for further reactions, but also react with haloarene, alkenes, terminal alkynes, amines and other organometallics directly in the presence of transition metal catalysts to form various products. There are two ways to prepare bromoarenes according to reaction conditions. One is to use bromine, zero or high-valent bromine complexes without any oxidants, the other is to employ bromides with additional oxidants. Thus, normally atom economy is not high and a lot of waste is generated. In the oxidative bromination of arenes, exploring more effective catalytic systems to utilize air as a “green” oxidant is a promising subject. In the past years, a few aerobic oxidative brominations of arenes were reported, but the catalytic oxidative bromination of arenes using air as oxidant at room temperature has been found rarely. Herein, after many investigations on catalytic system and