Lu Hong, Zhao Tian-Tian, Bai Jin-Hua, Ye Dan, Xu Peng-Fei, Wei Hao
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an, 710069, China.
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
Angew Chem Int Ed Engl. 2020 Dec 21;59(52):23537-23543. doi: 10.1002/anie.202010244. Epub 2020 Oct 19.
Highly selective divergent coupling reactions of benzocyclobutenones and indoles, in which the chemoselectivity is controlled by catalysts, are reported herein. The substrates undergo C2(indole)-C8(benzocyclobutenone) coupling to produce benzylated indoles and benzo[b]carbazoles in the Ni- and Ru-catalyzed reactions. A completely different selectivity pattern C2(indole)-C2(benzocyclobutenone) coupling to form arylated indoles is observed in the Rh-catalyzed reaction. Preliminary mechanistic studies suggest C-H and C-C activations in the reaction pathway. Synthetic utility of this protocol is demonstrated by the selective synthesis of three different types of carbazoles from the representative products.
本文报道了苯并环丁烯酮与吲哚的高选择性发散偶联反应，其中化学选择性由催化剂控制。在镍和钌催化的反应中，底物发生C2（吲哚）-C8（苯并环丁烯酮）偶联，生成苄基化吲哚和苯并[b]咔唑。在铑催化的反应中，观察到完全不同的选择性模式，即C2（吲哚）-C2（苯并环丁烯酮）偶联形成芳基化吲哚。初步机理研究表明反应途径中存在C-H和C-C活化。该方法的合成实用性通过从代表性产物选择性合成三种不同类型的咔唑得到了证明。
