Copper-Catalyzed Oxidative Amination of Benzoxazoles via C−H and C−N Bond Activation: A New Strategy for Using Tertiary Amines as Nitrogen Group Sources
method for oxidative amination of azoles with tertiary aminesviacopper-catalyzed C−H and C−Nbond activation has been developed. This protocol can be performed in the absence of external base and only requires atmospheric oxygen as oxidant. The catalyst system is very simple and efficient, which opens a new way for using tertiary amines as nitrogen group sources for C−Nbondformation reactions.
Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources
作者:Rui Wang、Hong Liu、Liang Yue、Xiao-ke Zhang、Qiu-yuan Tan、Ruo-lin Pan
DOI:10.1016/j.tetlet.2014.02.070
日期:2014.4
A transition metal-free method for the directamination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.
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</sup>Bu<sub>4</sub>NI-catalyzed direct amination of benzoxazoles with tertiary amines using TBHP as oxidant under microwave irradiation
Abstract A facile, efficient, and practical method for nBu4NI-catalyzed direct C–H amination of benzoxazoles with tertiary amines has been developed. The system could be performed in the absence of metal catalyst and only requires tert-butyl hydroperoxide as oxidant under microwave irradiation. A variety of substituted benzoxazol-2-amines were synthesized with moderate to good yield.
Cooperative Catalysis with Aldehydes and Copper: Development and Application in Aerobic Oxidative CH Amination at Room Temperature
作者:Yinjun Xie、Bo Qian、Pan Xie、Hanmin Huang
DOI:10.1002/adsc.201200944
日期:2013.5.3
formation of an aminal, hydrolysis of the aminal to generate the copper‐amide species, subsequent CH amination and re‐oxidation of copper(I) to copper(II) by oxygen. It not only provides an efficient method to realize the oxidative CH amination of benzoxazoles with free amines at room temperature, but also paves the way for establishing new CN bond formation reactions by using this efficient cooperative
In this article, a facile, efficient and practical method for Ni-catalyzed directC–H amination of benzoxazole with secondary amines has been developed. This procedure requires Ni(OAc)2·4H2O as catalyst, TBHP as oxidant and acid as the additive. A variety of substituted benzoxazol-2-amines were synthesized in moderate to good yields.