Oxidation of alkynes using ammonium persulfate and diphenyl diselenide as catalyst in aqueous media leads to 1,2-unprotected dicarbonyl derivatives or to hemiacetals starting from terminal alkynes.
S. Santoro, B. Battistelli, B. Gjoka, C.-w. S. Si, L. Testaferri, M. Tiecco, C. Santi, Synlett, 2010, 1402-1406.
An environmentally benign protocol for the iodination of activated aromatics, such as phenols, anilines, and hydroxycoumarins, using inexpensive commercially available potassium iodide and ammonium peroxodisulfate in aqueous methanol at room temperature provides predominantly ortho-monoiodinated products. This acid-free method is compatible with various oxidizable functional groups.
N. C. Ganguly, S. K. Barik, S. Dutta, Synthesis, 2010, 1467-1472.
An unprecedented Rh-catalyzed direct methylation of ketones with N,N-dimethylformamide shows a broad substrate scope. Mechanistic studies suggest that DMF delivers a methylene fragment followed by a hydride during the methylation process.
Y. Li, D. Xue, W. Lu, C. Wang, Z.-T. Liu, J. Xiao, Org. Lett., 2014, 16, 66-69.
N-Acyl amino acids can be converted by oxidative decarboxylation induced by Ag+/Cu2+/S2O82- at room temperature in water into imides in good yields. Both N-benzoylvaline and N-benzoylleucine gave N-formylbenzamide, which possibly results from oxidative cleavage of an enamide intermediate.
W. Huang, M. Wang, H. Yue, Synthesis, 2008, 1342-1344.
(NH4)2S2O8 mediates a metal-free three-component alkene oxyalkynylation using H2O or alcohol as oxygenation agent. The reversed regioselectivity should be dictated by an alkene radical cation intermediate.
Y. Li, R. Lu, S. Sun, L. Liu, Org. Lett., 2018, 20, 6836-6839.
NaI-Mediated Acetamidosulphenylation of Alkenes with Nitriles as the Nucleophiles: A Direct Access to Acetamidosulfides
Y. Zheng, Y. He, G. Rong, X. Zhang, Y. Wang, K. Dong, X. Xu, J. Mao, Org. Lett., 2015, 17, 5444-5447.
The use of ammonium persulfate as an oxidant and iodide as an iodine source enables stereospecific diiodination of alkynes under mild conditions in water. The highly efficient reaction provides a broad range of (E)-diiodoalkenes.
Q. Jiang, J.-Y. Wang, C.-C. Guo, Synthesis, 2015, 47, 2081-2087.
An efficient copper-catalyzed sulfenylation and selenylation of 2,3-allenoic acids with disulfides or diselenides afford various 4-sulfenylated and 4-selenylated butenolides in good yields via tandem radical addition/intramolecular cyclization processes. Moreover, 4-sulfonylated butenolides could also be obtained by sulfenylation of 2,3-allenoic acids and subsequent oxidation.
Y.-X. Xin, S. Pan, Y. Huang, X.-H. Xu, F.-L. Qing, J. Org. Chem., 2018, 83, 6101-6109.