960化工网
Silver-catalyzed nitration/annulation of 2-alkynylanilines for a tunable synthesis of nitrated indoles and indazole-2-oxides†
Tian-Shu Zhang,Rong Wang,Pei-Jun Cai,Wen-Juan Hao,Shu-Jiang Tu,Bo Jiang
Organic Chemistry Frontiers Pub Date : 07/08/2019 00:00:00 , DOI:10.1039/C9QO00715F
Abstract

Two new types of silver-catalyzed nitration–annulations of 2-alkynylanilines with tert-butyl nitrite (TBN) were reported, leading to the selective formation of a variety of nitrated indoles and indazole-2-oxides by changing the N-protection of 2-alkynylanilines. Ag-Catalyzed nitration–annulation of N-sulfonyl 2-alkynylanilines without C4 substituents afforded 5-nitroindoles under neutral-redox conditions, whereas the presence of C5 substituents gave 7-nitroindoles through silver catalysis. N-Methyl 2-alkynylanilines underwent a completely different process to furnish aroyl indazole-2-oxides.

Graphical abstract: Silver-catalyzed nitration/annulation of 2-alkynylanilines for a tunable synthesis of nitrated indoles and indazole-2-oxides
平台客服
平台客服
平台在线客服