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Synthesis of Novel Functionalized Polymers for the Diastereoselective Protonation of Chiral Enolates
Author(s) -
Mackenstedt Marc,
Krause Norbert
Publication year - 2004
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/ejoc.200400429
Subject(s) - chemistry , protonation , enol , polymer , silylation , styrene , lithium (medication) , monomer , polymer chemistry , selectivity , polymerization , radical polymerization , organic chemistry , catalysis , copolymer , medicine , ion , endocrinology
The polymeric, chelating proton donors 7 and 8 were synthesized by radical polymerization of the monomers 5 / 6 with different amounts of styrene. Protonation of chiral lithium enolates derived from silyl enol ethers 9 gave cis / trans ratios of up to 94:6 ( 10a ) and 99:1 ( 10b ), respectively. The polymers can be recycled and used repeatedly without appreciable loss of selectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)