A new route to substituted furocoumarins <i>via</i> copper-catalyzed cyclization between 4-hydroxycoumarins and ketoximes
作者:Tuong A. To、Yen H. Vo、Anh T. Nguyen、Anh N. Q. Phan、Thanh Truong、Nam T. S. Phan
DOI:10.1039/c8ob01064a
日期:——
A newroute to substituted furocoumarins via copper-catalyzed cyclization between 4-hydroxycoumarins and ketoximes was developed. CuBr2 exhibited higher activity than other copper salts, affording the desired furocoumarins in high yields. The transformation proceeded readily in the absence of stoichiometric external oxidants. The significance of this synthetic strategy would be (1) the easily available
We describe herein a palladium-catalyzed Heck-type reaction of O-acetyl ketoximes and allylicalcohols to pyridines. This protocol allows robust synthesis of pyridines and azafluorenones in good to excellent yields with...
Elemental tellurium mediated synthesis of 2-(trifluoromethyl)oxazoles using trifluoroacetic anhydride as reagent
作者:Beibei Luo、Zhiqiang Weng
DOI:10.1039/c8cc05670f
日期:——
An elemental tellurium mediated synthesis of 2-(trifluoromethyl)oxazoles from the reaction of acetophenone oxime acetates with trifluoroacetic anhydride has been developed. This new tandem cyclization proceeds in good to excellent yields via a SET reduction followed by a 5-endo-trig pathway. Some of the title compounds showed fungicidal and insecticidal activities.
An efficient synthesis of polysubstituted pyrroles via copper-catalyzed coupling of oxime acetates with dialkyl acetylenedicarboxylates under aerobic conditions
A Cu-catalyzed [3+2]-type condensation reaction of oxime acetates and dialkyl acetylenedicarboxylates that provides highly substituted pyrroles under aerobic conditions is described. The newly formed pyrroles are easily employed for further transformations to prepare pyrrolo[2,1-a]isoquinoline skeletons.