Iminophosphorane-mediated synthesis of 2H-indazole derivatives: preparation of 2,3-diamino-2H-indazoles by intramolecular trapping of phosphazides and 1H-1,2,4-triazolo[2,3-b]indazoles by a tandem aza-Wittig/heterocumulene-mediated strategy
Intramolecular trapping of a phosphazide by an imine: Formation of 2,3-diamino-2H-indazole derivatives from o-azidobenzaldimines and tertiary phosphines
作者:Pedro Molina、Antonio Arques、María Victoria Vinader
DOI:10.1016/s0040-4039(01)93353-2
日期:——
Treatment of o-azidobenzaldimines with tertiaryphosphines in dichloromethane at 0°C gave the corresponding 2,3-diamino-2H-indazole derivatives in good yields via the Staudinger reaction followed by cyclization of the intermediate phosphazide.
Consecutive Condensation, C–N and N–N Bond Formations: A Copper- Catalyzed One-Pot Three-Component Synthesis of 2<i>H</i>-Indazole
作者:Manian Rajesh Kumar、Ahbyeol Park、Namjin Park、Sunwoo Lee
DOI:10.1021/ol201409j
日期:2011.7.1
2H-Indazoles are synthesized using copper-catalyzed, one-pot, three-component reactions of 2-bromobenzaldehydes, primary amines, and sodium azide. A copper catalyst plays the key role in the formation of C-N and N-N bonds. This method has a broad substrate scope with a high tolerance for a variety of functional groups.