Ionic liquids, that is molten salts, may represent activating and stabilizing solvents for C–C coupling reactions. In particular, tetrabutylammonium bromide (TBAB) is particularly suitable for Heck reactions as it enhances reaction rates. In the presence of tetrabutylammonium acetate as base, palladium complex with benzothiazolidene as ligands as well palladium acetate are transformed to Pd-nanoparticles which allow regio- and stereo-specific Heck reactions with very high TON and TOF. Beside this, TBAB enhances, by solvation, the formation and reactivity of carbanions. A comparative study on effects exerted by different ionic liquids on catalyst stabilization, reaction rates and regioand stereo-selectivity in the C–C coupling reactions is also reported.
Regio- and Stereo-Selective Carbon-Carbon Bond Formation in Ionic Liquids
NACCI, Angelo;MONOPOLI A.
2004-01-01
Abstract
Ionic liquids, that is molten salts, may represent activating and stabilizing solvents for C–C coupling reactions. In particular, tetrabutylammonium bromide (TBAB) is particularly suitable for Heck reactions as it enhances reaction rates. In the presence of tetrabutylammonium acetate as base, palladium complex with benzothiazolidene as ligands as well palladium acetate are transformed to Pd-nanoparticles which allow regio- and stereo-specific Heck reactions with very high TON and TOF. Beside this, TBAB enhances, by solvation, the formation and reactivity of carbanions. A comparative study on effects exerted by different ionic liquids on catalyst stabilization, reaction rates and regioand stereo-selectivity in the C–C coupling reactions is also reported.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
