Regioselective Dichotomy in Ru(II)-Catalyzed C–H Annulation of Aryl Pyrazolidinones with 1,3-Diynes
作者:Geetanjali S. Sontakke、Chiranjit Ghosh、Kuntal Pal、Chandra M. R. Volla
DOI:10.1021/acs.joc.2c01691
日期:2022.11.4
Herein, we present a substrate-controlled regiodivergent strategy for the selective synthesis of C3 or C2-alkynylated indoles via ruthenium-catalyzed [3 + 2]-annulation of readily available pyrazolidinones and 1,3-diynes. Remarkably, C3-alkynylated indoles were obtained in good yields when 1,4-diarylbuta-1,3-diynes were employed as the coupling partners. On the other hand, dialkyl-1,3-diynes led to
在这里,我们提出了一种底物控制的区域发散策略,用于通过钌催化的容易获得的吡唑烷酮和 1,3-二炔的 [3 + 2] 环化选择性合成 C3 或 C2-炔基化吲哚。值得注意的是,当使用 1,4-diarylbuta-1,3-diynes 作为偶联伙伴时,C3-炔基化吲哚的收率很高。另一方面,二烷基-1,3-二炔导致选择性形成C2-炔基化吲哚。该策略的主要特点是操作简单的条件和无外部氧化剂、范围广和底物可切换的吲哚合成。放大反应和进一步的转化扩大了协议的综合效用。