Separation of planar chiral ferrocene derivatives on beta-cyclodextrin-based polymer supports prepared via ring-opening metathesis graft-polymerization.
A series of beta-cyclodextrin (beta-CD) based chiral stationary phases (CSPs) were synthesized by ring-opening metathesis graft polymerization of various norborn-2-ene (NBE) substituted CDs. Chiral selectors based on endo/exo-6-O-(norborn-2-ene-5-ylmethoxymethylsilyl)-beta-CD, tris(endo/exo-6-O-norborn-2-ene-5-ylmethoxymethylsilyl)-beta-CD, tetrakis(endolexo-6-0-norborn-2-ene-5-ylmethoxymethylsilyl)-beta-CD, hexakis(endo/exo-6-O-norborn-2-ene-5-ylmethoxymethylsilyl)-beta-CD and tetrakis(endo-6-O-norborn-2-ene-5-carboxyl)-beta-CD were grafted onto Nucleosil 300-5 using well-established grafting procedures. CSPs were investigated for their separation capabilities for a series of the planar chiral ferrocene derivatives, rac-ferroceno[2,3a]inden-1-one (1a, 1b), rac-6-(3-hydroxy-3-methylbut-1-yn-1-yl)ferroceno[2,3a]inden-1-one (2a, 2b), rac-ferrocene[2,3a]indene (3a, 3b), rac-endo 1-methoxy-1-allylferroceno[2,3a]indene (4a, 4b) and rac-1,4-dihydroxybutylferrocene (5a, 5b). Compounds la, lb and 2a, 2b bearing a carbonyl group were successfully separated on these CSPs, while compounds 3-5 do not undergo enantioselective interaction under the conditions applied. General aspects of separation as well as mechanistic implementations are discussed.
Mayr
Betina
B
Institute of Analytical Chemistry and Radiochemistry, University of Innsbruck, Austria.
Schottenberger
Herwig
H
Elsnerb
Olaf
O
Buchmeiser
Michael R
MR
D003505:Cyclodextrins / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry / Q000302:isolation & purification*; D000075163:Metallocenes; D011108:Polymers / Q000737:chemistry*; D013057:Spectrum Analysis; D013237:Stereoisomerism; D013696:Temperature; D047392:beta-Cyclodextrins
D003505:Cyclodextrins; D005296:Ferrous Compounds; D000075163:Metallocenes; D011108:Polymers; D047392:beta-Cyclodextrins; C031215:betadex; C004998:ferrocene