[reaction: see text] The rhodium(I)-catalyzed methylenation of ketones using trimethylsilyldiazomethane proceeds to give the corresponding alkenes in good yields (60-97%). The use of an excess of 2-propanol and 1,4-dioxane as a solvent were instrumental to obtain the desired alkenes in high yields. Superior results were achieved with the rhodium(I)-catalyzed methylenation in comparison with the standard
Copper−Carbene Complexes as Catalysts in the Synthesis of Functionalized Styrenes and Aliphatic Alkenes
作者:Hélène Lebel、Michaël Davi、Silvia Díez-González、Steven P. Nolan
DOI:10.1021/jo061781a
日期:2007.1.1
2-propanol. The copper catalysts are not only inexpensive compared to rhodium complexes, but they also exhibit better functional group compatibility with aromatic aldehydes and ketones. Indeed very high yields were obtained for the formation of styrenes containing nitro, trifluoromethyl, amino, and ester groups, as well as for pyridine-, pyrrole-, and indole-substituted alkenes.