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Synlett 2005(19): 2993-2995  
DOI: 10.1055/s-2005-921886
LETTER
© Georg Thieme Verlag Stuttgart · New York

An Improved Protocol for the Synthesis and Nanofiltration of Kim and Park’s Aminocyclopentadienyl Ruthenium Chloride Racemisation Catalyst

Emma J. Gibbinsa, Jacob L. Irwinb, Andrew G. Livingston*a, Jennifer C. Muirb, Darrell A. Pattersona, Chayaporn Roengpithyaa, Paul C. Taylor*b
a Department of Chemical Engineering, Imperial College, London, SW7 2AZ, UK
Fax: +44(20)75945604; e-Mail: A.Livingston@imperial.ac.uk;
b Department of Chemistry, The University of Warwick, Coventry, CV4 7AL, UK
Fax: +44(24)76524112; e-Mail: P.C.Taylor@warwick.ac.uk.;
Further Information

Publication History

Received 27 July 2005
Publication Date:
27 October 2005 (online)

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Abstract

An improved synthesis of aminocyclopentadienyl ­ruthenium chloride catalyst 1 is reported. A combination of catalyst 1 and phosphazene base 3 is shown to effect racemisation of 1-­phenylethanol. Removal of 1 and 3 by nanofiltration is a practical and effective purification method.

Key words

racemisation - ruthenium - phosphazene - nanofiltration

9

Starmem is a trademark of W. R. Grace and Co, USA. Starmem 120 and 122 have nominal MWCO of 200 and 220 g mol-1. MWCO is determined from a plot of rejection vs. molecular weight for n-alkanes in toluene.

11

Recovery of species i (Reci) is defined as the molar percentage permeated through the membrane and is calculated using Equation [1] :
Retention of species i (Reti) is defined as the molar percentage retained by the membrane and is calculated using Equation [2] , where Ci,r and Ci,p and Vr and Vp are the molar concentrations of i and volumes, respectively, in the retentate and permeate:

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StarmemTM membranes and the nanofiltration cell were obtained from Membrane Extraction Technology Ltd, UK (www.membrane-extraction-technology.com).