1-Boc-吲哚-2-硼酸衍生物的合成

Preparation of 1-Boc-2-indoyl borates

1-Boc-吲哚-2-硼酸衍生物是一类重要的有机中间体,广泛用于卤代芳烃参与的Suzuki-Miyaura偶联反应,从而构建复杂吲哚化合物.为了合成这类吲哚硼酸衍生物,以邻甲基硝基苯的衍生物(1a-1g)为起始原料,通过与DMFDMA、THP进行反应并进行浓缩结晶合成对应的烯胺;烯胺与还原剂进行还原关环得到吲哚衍生物;吲哚衍生物与二碳酸二叔丁酯反应完成对吲哚的保护;Boc保护的吲哚衍生物在低温无水无氧条件下与硼酸三异丙酯、LDA反应引入硼酸基团共4步反应,成功合成了包括6-苄氧基-1-Boc-吲哚-2-硼酸在内的共计7种吲哚硼酸衍生物(5a-5g),其结构经^1H NMR、^13 C NMR、IR和MS表征.

1-Boc-2-indoyl borates derivatives are the important organic intermediates that are widely used in the Suzuki-Miyaura coupling reaction involving halogenated aromatic hydrocarbons to construct complex indole compounds.In order to synthesize this kind of indole boric acid derivatives,seven indole boric acid derivatives(5a-5g)including 6-benzyloxy-1-Boc-indole-2-boric acid were synthesized by the following 4 steps.Fristly,by using derivatives of o-methylnitrobenzene(1a-1g)as a starting material,the reaction is carried out by reaction with DMFDMA,THP and concentrated crystallization to synthesize the corresponding enamine.Secondly,enamine and reduce agent for reduction and ring closure.The indole derivatives are reacted with(Boc)2 O to complete the protected indole.Finally,the Boc-protected indole is reacted with triisopropyl borate and LDA under low temperature and anhydrous anaerobic conditions to introduce boric acid groups.The structure of the final products were confirmed by ^1H NMR,^13C NMR,IR and MS.