TETRAHEDRON: ASYMMETRY Tetrahedron: Asymmetry 11 (2000) 3687–3692 Pergamon Preparation of chiral C 2 -symmetrical 1,1-disubstituted ferrocenes Angela Patti* and Giovanni Nicolosi Istituto CNR per lo Studio delle Sostanze Naturali di Interesse Alimentare e Chimico -Farmaceutico, Via del Santuario 110, I -95028 Valverde CT, Italy Received 27 June 2000; accepted 7 August 2000 Abstract A biocatalytic procedure for the resolution and concurrent desymmetrization of tetraacetoxyferrocene (±, meso )-2 is described. Enantiomerically pure (R,R )- and (S,S )-forms have been converted into the corresponding epoxide 6, a useful starting material for the preparation of polyfunctional C 2 -symmetric ferrocenes. © 2000 Elsevier Science Ltd. All rights reserved. 1. Introduction Homogeneous asymmetric catalysis with transition metal complexes is an active area of research 1 and great interest is directed toward the design and development of efficient ligands. Ferrocene ligands have gained much attention due to their peculiar chemical features, namely diastereoselective metallation on the cyclopentadienyl ring 2 and retentive nucleophilic displace- ment on the benzylic position, 3 which allow the preparation of a broad range of substituted derivatives. Numerous ferrocenyl ligands incorporating both planar and central chirality have proved very effective in several asymmetric catalytic processes. 4 More recently several C 2 -sym- metrical ferrocenes have been synthesized 5 and some ferrocenyldiphoshines have been used as catalysts in palladium-catalyzed reactions 6 or rhodium-catalyzed hydrogenation and hydrosilylation. 7 Stereoselective reduction of 1,1-ferrocenyldiketones provides access to C 2 -symmetrical fer- rocenes possessing only central chirality 8 and the related 1,1-ferrocenyldiamines have been used successfully as ligands for ruthenium-catalyzed transfer hydrogenation. 9 We have recently developed a chemoenzymatic method to prepare chiral ferrocenyl derivatives with a stereogenic carbon  to the cyclopentadienyl ring. 10 Here we report the extension of that procedure to 1,1-bis[(2,3-dihydroxy)propyl]ferrocene, (±, meso )-1 whose (R,R )- and (S,S )-forms * Corresponding author. Tel: +39 095 7212136; fax: +39 0957212141; e-mail: patti@issn.ct.cnr.it 0957-4166/00/$ - see front matter © 2000 Elsevier Science Ltd. All rights reserved. PII:S0957-4166(00)00299-8