Rhodium(III)-Catalyzed<i>N</i>-Nitroso-Directed CH Addition to Ethyl 2-Oxoacetate for Cycloaddition/Fragmentation Synthesis of Indazoles
作者:Jinsen Chen、Pei Chen、Chao Song、Jin Zhu
DOI:10.1002/chem.201404506
日期:2014.10.27
RhIII‐catalyzed N‐nitroso‐directed CH addition to ethyl 2‐oxoacetate allows subsequent construction of indazoles, a privileged heterocycle scaffold in synthetic chemistry, through the exploitation of reactivity between the directing group and installed group. The formal [2+2] cycloaddition/fragmentation reaction pathway identified herein, a unique reactivity pattern hitherto elusive for the N‐nitroso
A highly selective sp3 C–N cleavage of tertiary anilines was achieved using the TBN/TEMPO catalyst system. When N,N-diaklylanilines (alkyl, benzyl) were employed, the N–CH3 bond was selectively cleaved via radical C–Hactivation. Moreover, when the allyl group was installed, totally reverse selectivity was observed. It is worth noting that the solvent effect is also crucial to obtain high reaction
Regioselective Synthesis of 2-Alkenylindoles and 2-Alkenylindole-3-carboxylates through the Cascade Reactions of <i>N</i>-Nitrosoanilines with Propargyl Alcohols
作者:Xia Song、Cai Gao、Bin Li、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.joc.8b01098
日期:2018.8.3
In this paper, a novel and efficient synthesis of 2-alkenylindoles and 2-alkenylindole-3-carboxylates via the cascade reactions of N-nitrosoanilines with propargyl alcohols is presented. Mechanistically, the formation of the title compounds is triggered by a Rh(III)-catalyzed C(sp2)–H alkenylation of N-nitrosoaniline with propargyl alcohol followed by the simultaneous intramolecular amination/cyclization