Polymeric monolith containing TI-TADDOLate has been synthesized by thermally induced radical solution polymerization of a monomeric mixture containing TADDOL monomer, styrene and divinylbenzene, using azobisisobutyronitril (AIBN) as the radical initiator (Scheme 10). This catalyst was used for Diels-Alder reaction and diethyl zinc addition to benzaldehyde.13
Scheme 10
Modified poly(ethylene glycol) (MeOPEG) supported chiral bisoxazoline ligand was synthesized for enantioselective carbon-carbon bond forming reactions such as Diels-Alder reaction, cyclopropanation and ene reaction in the presence of Cu(OTf)2 (Scheme 11).14
Scheme 11
Umani-Ronchi and coworkers have synthesized polymer supported indium(III) catalyst from Amberlyst-15 for ring opening reaction of enantiopure epoxides with N-methylindole as well as thiophenol derivatives (Scheme 12).15
Scheme 12
Janda and coworkers developed a new method for the synthesis of cross-linked copolymer witj Yb(OTf)3 (scheme 12). The immobilized catalyst was tested for Mannich as well as Diels-Alder reaction.16
Scheme 13