This paper reports nitrosoallene-mediated synthesis of alpha-substituted enoximes. Nucleophilic substitution of nitrosoallenes, a novel chemical species prepared from allenyl N-hydroxysulfonamides, afforded alpha-functionalized enoximes. Introduction of various nucleophiles proceeded smoothly to form C-N, C-O, C-S, C-F, and C-C bonds in the presence of azodicarboxylates.
Regioselective Rapid Synthesis of Fully Substituted 1,2,3-Triazoles Mediated by Propargyl Cations
Regioselective rapid triazole syntheses at low temperature are described. Organic azides and propargyl cations generated by acids gave fully substituted 1H-1,2,3-triazoles. Most reactions could be performed in 5 min at not only rt but also -90 degrees C. Both terminal and internal alkynes were acceptable, and the sterically bulky substituents could afford the products smoothly. Various types of three-component coupling reactions were demonstrated, and the presence of allenylaminodiazonium intermediates was indicated.