Cobalt-Catalyzed Aerobic Oxidative Cyclization of 2-Aminophenols with Isonitriles: 2-Aminophenol Enabled O<sub>2</sub> Activation by Cobalt(II)
作者:Jiaqi Liu、Jessica M. Hoover
DOI:10.1021/acs.orglett.9b01384
日期:2019.6.21
An aerobic cobalt-catalyzed oxidative cyclization of 2-aminophenols and isonitriles is reported. These additive-free conditions furnish a variety of substituted 2-aminobenzoxazoles in moderate to excellent yields. A series of control experiments and spectroscopic studies point to the importance of 2-aminophenol coordination in enabling the aerobic oxidation of cobalt(II).
Silver-Mediated Direct Amination of Benzoxazoles: Tuning the Amino Group Source from Formamides to Parent Amines
Going to the source: Formamides or parentamines were used as an aminogroupsource for the silver‐mediated amination of benzoxazoles. Although reactions with formamides proceeded at high temperatures, the directamination with amines took place under much milder conditions (see scheme). Optically active aminogroups could also be installed without racemization.