The use examples of ionic liquids


1. Sonogashira coupling reaction

Features:addition-free of a Copper catalyst
(1) T.Fukuyama,M.Shinmen,S.Nishitani,M.sato, and I.Ryu,Org.Lett.,4,1691(2002) Other coupling reactions:Mizoroki-Heck reaction(2)(3)
(2)A.J.Carmichael,M.J.Earle,J.D.Holbrey,P.B.McCormac,K.R.Seddon,Org.Lett.,1,997(1999)
(3)S.Liu,T.Fukuyama,M.Sato,and I.Ryu,Synlett,1814(2004)

2. Wittig reaction
2-1
Feature:Ionic liquids are recyclable without purification.
(4) Tomoya Kitazume,etc.(Tokyo Institute of Technology) patent:2001-247508

2-2
(5)V.L.Boulaire,R.Gree,Chem.Commun.,2195(2000)

3. Aldol reaction


Feature:When you use the reaction solvent repeatedly, TfOH does not need addition so that it is maintained by the ionic liquid.
(6)Hiroshi Nakano,a doctoral dissertation (2001)

4.Aza-Diels-Alder reaction
Feature:When you use the reaction solvent repeatedly, Lewis acid does not need addition so that it is immobilized by the ionic liquid.

As above, various organic reactions can use ionic liquids and be able to recycle them with having immobilized a catalyst, so they are said Green Solvent. In Diels-Alder reaction, the example that 11 times of repetition uses were possible without yield fall has been reported(8). As for these new liquids consisting only of ions, more new functions are expected in future.

(8) C.E.Song,W.H.Shim,E.J.Roh,S.-gi Lee,J.H.Choi,Chem.Commun.,2001,1122