TY - JOUR
T1 - Polymer-bound aluminium salen complex as reusable catalysts for CO 2 insertion into epoxides
AU - Alvaro, Mercedes
AU - Baleizao, Carlos
AU - Carbonell Llopis, Esther
AU - El Ghoul, Mostafa
AU - García, Hermenegildo
AU - Gigante, Barbara
PY - 2005/12/19
Y1 - 2005/12/19
N2 - Two polymeric aluminium salen complexes in where the backbones are either a partially crosslinked polystyrene [(Al(salen)/PS)] or poly(ethylene glycol bismethacrylate) [(Al(salen)/PEA)] have been synthesised and used for the carbon dioxide insertion into epoxides to form cyclic carbonates. The catalytic activity of these polymers is similar to that of the unsupported aluminium salen complexes, and the polymeric catalysts can be easily separated from the reaction mixture and reusable in consecutives runs. The activity and reusability of the polymeric salen complex depends on the nature of the polymer: PEA being a polymer with a high oxygen content in the backbone enhances the initial activity as compared to PS, but Al(salen)/PEA exhibits lower stability as compared to Al(salen)/PS and a Al depletion occurs upon use. The presence of nucleophiles such as N-methylimidazole or N,N-dimethylaminopyridine in excess increases the catalytic activity of the polymeric Al(salen) catalyst. Also polymeric nucleophiles have been found to be suitable reusable co-catalysts for this reaction.
AB - Two polymeric aluminium salen complexes in where the backbones are either a partially crosslinked polystyrene [(Al(salen)/PS)] or poly(ethylene glycol bismethacrylate) [(Al(salen)/PEA)] have been synthesised and used for the carbon dioxide insertion into epoxides to form cyclic carbonates. The catalytic activity of these polymers is similar to that of the unsupported aluminium salen complexes, and the polymeric catalysts can be easily separated from the reaction mixture and reusable in consecutives runs. The activity and reusability of the polymeric salen complex depends on the nature of the polymer: PEA being a polymer with a high oxygen content in the backbone enhances the initial activity as compared to PS, but Al(salen)/PEA exhibits lower stability as compared to Al(salen)/PS and a Al depletion occurs upon use. The presence of nucleophiles such as N-methylimidazole or N,N-dimethylaminopyridine in excess increases the catalytic activity of the polymeric Al(salen) catalyst. Also polymeric nucleophiles have been found to be suitable reusable co-catalysts for this reaction.
KW - CO insertion
KW - Cyclic carbonates
KW - Heterogenoeus catalysis
KW - Polyethylenglycol as solvent
UR - http://www.scopus.com/inward/record.url?scp=27944446475&partnerID=8YFLogxK
U2 - 10.1016/j.tet.2005.07.114
DO - 10.1016/j.tet.2005.07.114
M3 - Article
AN - SCOPUS:27944446475
SN - 0040-4020
VL - 61
SP - 12131
EP - 12139
JO - Tetrahedron
JF - Tetrahedron
IS - 51
ER -