The chemoselective addition of tetraallyltin to dialkyl, alkenyl– alkyl, and alkynyl–alkyl ketones can be performed with high yields in N-methyl-N-butylpyrrolidinium trifuoromethansulfonate (MBP-Tf). Other room temperature ionic liquids (RTILs) can also be successfully employed if some sulfonic acid is added. The reaction is very sensitive to the electronic properties of the substrate. Aryl alkyl ketones bearing electron-withdrawing substituents behave like dialkyl ketones and react promptly; on the contrary, electron-rich aryl alkyl ketones react sluggishly, which allows selective competitive allylation of dialkyl substrates to occur. The ionic liquid solvent can be easily recycled, which meets the green chemistry principles of selectivity and reuse of chemicals. NMR spectroscopic data support the formation of tin-triflate catalysts in situ.
Galletti P., Moretti F., Samorì C., Tagliavini E. (2009). Chemoselective Allylation of Ketones in Ionic Liquids Containing Sulfonate Anions. CHEMSUSCHEM, 2, 1045-1050 [10.1002/cssc.200900198].
Chemoselective Allylation of Ketones in Ionic Liquids Containing Sulfonate Anions
GALLETTI, PAOLA;MORETTI, FABIO;SAMORI', CHIARA;TAGLIAVINI, EMILIO
2009
Abstract
The chemoselective addition of tetraallyltin to dialkyl, alkenyl– alkyl, and alkynyl–alkyl ketones can be performed with high yields in N-methyl-N-butylpyrrolidinium trifuoromethansulfonate (MBP-Tf). Other room temperature ionic liquids (RTILs) can also be successfully employed if some sulfonic acid is added. The reaction is very sensitive to the electronic properties of the substrate. Aryl alkyl ketones bearing electron-withdrawing substituents behave like dialkyl ketones and react promptly; on the contrary, electron-rich aryl alkyl ketones react sluggishly, which allows selective competitive allylation of dialkyl substrates to occur. The ionic liquid solvent can be easily recycled, which meets the green chemistry principles of selectivity and reuse of chemicals. NMR spectroscopic data support the formation of tin-triflate catalysts in situ.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
