Diallyldimethylammonium and trimethylvinylammonium ionic liquids—Synthesis and application to catalysis

New quaternary ammonium salts containing unsaturated substituents (allyl or vinyl) were synthesized. All of them were subjected to spectroscopic, elemental and thermogravimetric analyses. The above compounds are ionic liquids (Tm < 100 °C) and were applied to immobilization of three rhodium(I) complexes [Rh(PPh3)3Cl], [{Rh(μ-Cl)(cod)}2] and [{Rh(μ-OSiMe3)(cod)}2] as well as three platinum complexes at different oxidation states [Pt(PPh3)4], K2[PtCl4] and K2[PtCl6]. Homogeneous catalytic systems were obtained and employed in the biphasic process of hydrosilylation of octene and allyl glycidyl ether with 1,1,1,3,5,5,5-heptamethyltrisiloxane. Catalytic activities of all the systems were compared and the best one was selected. The latter made it possible to recycle 10 times the same catalyst sample without a decrease in its activity and to easy separate the catalyst from the post-reaction mixture by decantation. The developed system is one of the most effective catalytic systems for hydrosilylation known to date.

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► Unsaturated substituent-containing ammonium ionic liquids were synthesized.
► Rhodium and platinum complexes were immobilized in ammonium ionic liquids.
► A very efficient catalytic system for hydrosilylation was developed.
► TON as high as 98,200 was obtained.
► Multiple use of catalyst without activity decrease was achieved.