Chemoselective allylation of ketones in ionic liquids containing sulfonate anions.
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
Paola
P
Centro Interdipartimentale di Ricerca per le Scienze Ambientali, Università di Bologna, Via Sant'Alberto 163, 48123 Ravenna, Italy.
Moretti
Fabio
F
Samorì
Chiara
C
Tagliavini
Emilio
E
D000498:Allyl Compounds / Q000737:chemistry*; D000838:Anions / Q000737:chemistry; D002384:Catalysis; D055772:Green Chemistry Technology / Q000379:methods*; D052578:Ionic Liquids / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008698:Mesylates / Q000138:chemical synthesis / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013451:Sulfonic Acids / Q000737:chemistry*; D013696:Temperature; D014001:Tin / Q000737:chemistry
D000498:Allyl Compounds; D000838:Anions; D052578:Ionic Liquids; D007659:Ketones; D008698:Mesylates; D009942:Organometallic Compounds; D012997:Solvents; D013451:Sulfonic Acids; D014001:Tin; C012077:trifluoromethanesulfonic acid