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Polystyrene Resins Incorporating BINOL Units: New Materials For Asymmetric Catalysis
Author(s) -
Herres Sonja,
Hesemann Peter,
Moreau Joël J. E.
Publication year - 2003
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/1099-0690(200301)2003:1<99::aid-ejoc99>3.0.co;2-q
Subject(s) - polystyrene , diethylzinc , chemistry , enantioselective synthesis , benzaldehyde , styrene , polymer chemistry , catalysis , polymerization , polymer , organic chemistry , copolymer
The radical crosslinking polymerization of styrene with ( R )‐divinyl‐BINOL derivatives results in the formation of reticulated polystyrene networks containing protected ( R )‐BINOL entities at each junction of the polystyrene chains. The generation of polystyrene‐immobilized free ( R )‐BINOL was performed by cleaving the protecting ether groups under acidic conditions. The resulting materials containing optically active BINOL units were tested as chiral ligands in the enantioselective addition of diethylzinc to benzaldehyde. The catalytic properties of the polymer gels were shown to be highly dependent on the degree of reticulation: in the best cases, the resins incorporating ( R )‐BINOL units showed activities and selectivities similar to those of molecular ( R )‐BINOL. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)