Journal of Chromatography A, 907 (2001) 47–56 www.elsevier.com / locate / chroma Chiral b-cyclodextrin-based polymer supports prepared via ring-opening metathesis graft-polymerization * Betina Mayr, Frank Sinner, Michael R. Buchmeiser Institute of Analytical Chemistry and Radiochemistry, University of Innsbruck, Innrain 52A, A-6020 Innsbruck, Austria Received 5 June 2000; received in revised form 28 September 2000; accepted 3 October 2000 Abstract A series of norborn-2-ene-derivatized b-cyclodextrins (b-CDs), 6-O-(norborn-2-ene-5-carboxyl)-b-CD (1), tetrakis(6-O- norborn-2-ene-5-carboxyl)-b-CD (2), 6-O-(7-oxanorborn-2-ene-5-carboxyl)-b-CD ( 3), 6-O-(6-norborn-2-ene-5-car- bonylaminohexoyl)-b-CD ( 4), 6-O-(norborn-2-ene-5-ylmethoxymethylsilyl)-b-CD ( 5), tris(6-O-norborn-2-ene-5-ylmethox- ymethylsilyl)-b-CD ( 6), tetrakis(6-O-norborn-2-ene-5-ylmethoxymethylsilyl)-b-CD ( 7) and hexakis(6-O-norborn-2-ene-5- ylmethoxymethylsilyl)-b-CD ( 8), have been synthesized. Compounds 1–3 were prepared via reaction of b-CD with norborn-2-ene-5-carboxylic chloride and 7-oxanorborn-2-ene-5-carboxylic chloride, respectively; compounds 5–8 were synthesized from norborn-2-ene-5-yl-methyldichlorosilane and b-CD, respectively. Compound 4 was accessible by reaction of norborn-2-ene-5-carboxylaminohexoyl chloride with b-CD. Compounds 1–8 were surface grafted onto norborn-2-ene- derivatized silica-based supports using ring-opening metathesis polymerization employing the ruthenium-based initiator bis(tricyclohexylphosphino)benzylideneruthenium dichloride [Cl Ru(CHC H )(PCy ) , Cy5cyclohexyl, 9]. Generally 2 6 5 3 2 speaking, the resulting chiral stationary phases (CSPs) I –VIII may be prepared with high reproducibility and may be used within a pH of 2–10. Thus, relative standard deviations (s ) of the mean resolution (R ) are ,7%. The CSPs were used n 21 s for the enantioselective separation of b-blockers, N-dansyl-, N-3,5-dinitrobenzoyl- and Fmoc-protected amino acids and were characterized in terms of chemical stability, selectivity (a 9) and resolution ( R ). Additionally, the role of the spacer as well s as influences of capacity and the degree of substitution of the b-CD moiety on the separation characteristics were determined.  2001 Elsevier Science B.V. All rights reserved. Keywords: Chiral stationary phases, LC; Surface grafting; Ring-opening metathesis polymerization 1. Introduction drugs and pharmaceuticals have been developed [1,2], a major part of chiral compounds is still Chiral stationary phases (CSPs) represent impor- produced as a racemate that needs to be separated tant tools for analytical and preparative scale sepa- carefully into both enantiomers by chiral high-per- rations of enantiomers. While various routes for the formance liquid chromatography (HPLC). Despite enantioselective synthesis of chemical compounds, the large variety of systems that are available so far [3–5], intense research still focuses on the econ- omical development of more stable, more efficient *Corresponding author. Tel.: 143-512-5075-184; fax: 143- and more selective chiral separation systems [6]. For 512-5072-677. practical reasons, CSPs consisting of surface modi- E-mail address: michael.r.buchmeiser@uibk.ac.at (M.R. Buch- meiser). fied supports are almost solely based on silica. 0021-9673 / 01 / $ – see front matter  2001 Elsevier Science B.V. All rights reserved. PII: S0021-9673(00)01008-6