Transformations of N-arylpropiolamides to indoline-2,3-diones and acids via C≡C triple bond oxidative cleavage and C(sp2)–H functionalization
作者:Ming-Bo Zhou、Yang Li、Xuan-Hui Ouyang、Jin-Heng Li
DOI:10.1007/s11426-019-9633-x
日期:2020.2
A new palladium-catalyzed oxidative conversion of N-arylpropiolamides and H2O to various indoline-2,3-diones and acids through the C≡C triple bond cleavage and C(sp2)–H functionalization is described, which is promoted by a cooperative action of catalytic CuBr2, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and O2. The method provides a practical tool for transformations of alkynes by means of a C–H
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.
The first example of Cu-catalyzed oxidation of indoles to isatin derivatives by the use of cheap aqueous tert-butyl peroxide as an oxidant was developed. This methodology is practically convenient and highly functional group tolerant, allowing a variety of indole derivatives to transform into the corresponding isatin derivatives in good yields.
A novel and temperature-controlled oxidation of α-hydroxyamides in the presence of IBX is described. The divergent one-pot synthesis of isatins and α-formyl amides was achieved in good to excellent yields under metal-free conditions. And these two mild methods can tolerate a variety of functional groups, and are operationally simple.
Double Carbonylation Using Glyoxal (HCOCOH): A Practical Copper-Promoted Synthesis of Isatins from Primary and Secondary Anilines
作者:Suzie Hui Chin Kuan、Wei Sun、Lu Wang、Chungu Xia、Meng Guan Tay、Chao Liu
DOI:10.1002/adsc.201700583
日期:2017.10.25
(glyoxal) as the double carbonylation reagent. Simple CuCl2⋅2H2O (copper(II) chloride dihydrate) was used as the oxidant for this transformation. Under optimized reaction conditions, various primary and secondary anilines were double-carbonylated to afford their corresponding isatins (26 examples, up to 80% yields).