Ionophilic phosphines: versatile ligands for ionic liquid biphasic catalysis.
Phosphine ligands bearing an imidazolium fragment were easily prepared by one-step radical chain addition of secondary phosphines to allyl or vinyl imidazolium salts. These ligands were used to prepare new ionophilic second generation Grubbs-type catalysts. The catalyst immobilized in 1-butyl-3-methyl imidazolium ILs shows good catalytic activity in RCM reactions of several substrates and, depending on the media employed, is stable up to eight cycles.