Guo Chenhao, Li Bin, Liu Huilai, Zhang Xiaopeng, Zhang Xinying, Fan Xuesen
Henan Key Laboratory of Organic Functional Molecules and Drug Innovation, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, School of Environment , Henan Normal University , Xinxiang , Henan 453007 , China.
Org Lett. 2019 Sep 20;21(18):7189-7193. doi: 10.1021/acs.orglett.9b01889. Epub 2019 Sep 4.
A dehydrogenative annulation of 2-arylindazoles with maleimides for the switchable synthesis of indazolo[2,3-]pyrrolo[3,4-]quinolinones or spiroindolo[1,2-]indazole-11,3'-pyrrolidinones is presented. Mechanistically, the formation of the title compounds involves a Rh(III)-catalyzed C-H metalation of 2-arylindazole, followed by maleimide insertion and intramolecular cyclization. Interestingly, the selectivity to form the fused or spiro compounds could be switched by resorting to different additives. The notable features of this protocol include simple substrates and excellent atom economy and regioselectivity.
本文报道了2-芳基吲唑与马来酰亚胺的脱氢环化反应，可用于选择性合成吲唑并[2,3-]吡咯并[3,4-]喹啉酮或螺吲唑并[1,2-]吲唑-11,3'-吡咯烷酮。从机理上讲，标题化合物的形成涉及Rh(III)催化的2-芳基吲唑的C-H金属化反应，随后是马来酰亚胺插入和分子内环化反应。有趣的是，通过使用不同的添加剂可以切换形成稠合或螺环化合物的选择性。该方法的显著特点包括底物简单、原子经济性和区域选择性优异。
