A simple and efficient tert-butyl hydroperoxide-mediated direct trifluoromethylation of indazoles using sodium trifluoromethanesulfinate has been developed under metal-free conditions. A library of trifluoromethylated products with broad functionalities has been synthesized with moderate to good yields. A radical mechanistic pathway has been proposed for the present protocol.
Potassium Persulfate-Mediated Thiocyanation of 2<i>H</i>
-Indazole under Iron-Catalysis
作者:Amrita Dey、Alakananda Hajra
DOI:10.1002/adsc.201801232
日期:2019.2.19
Potassium persulfate‐mediated thiocyanation of 2H‐indazoles has been developed using ammonium thiocyanate as thiocyanating agent under iron‐catalysis at room temperature. 2‐Aryl‐3‐thiocyanato‐2H‐indazoles are synthesized in good yields with a broad substrates scope. This methodology is also applicable for the selenocyanation of 2H‐indazoles. The mechanistic study suggests the reaction probably proceeds
Imino-λ<sup>3</sup>-iodane-Triggered Oxidative Ring-Opening of 2<i>H</i>-Indazoles to <i>ortho</i>-<i>N</i>-Acylsulfonamidated Azobenzenes
作者:Suvam Bhattacharjee、Alakananda Hajra
DOI:10.1021/acs.orglett.3c01498
日期:2023.6.9
An iminoiodane-enabled oxidative ring-opening of 2H-indazoles via C–N bond cleavage has been developed under metal-free reaction conditions. This methodology afforded a new array of unsymmetrical ortho-N-acylsulfonamidated azobenzenes with a wide functional group tolerance in good yields. The reaction potentially proceeds through the formation of a zwitterionic adduct, which is formed by the reaction
A visible-light-promoted regioselective C(sp2)–H/C(sp3)–H cross-dehydrogenative coupling between 2H-indazoles and ethers has been achieved using a catalyticamount of rose bengal as an organophotoredox-catalyst and tert-butyl hydroperoxide (TBHP) as an oxidant at ambient temperature underaerobicconditions. A variety of C-3 oxyalkylated 2H-indazoles have been synthesized in moderate to good yields