Hydrolytic Kinetic Resolution of Epoxides

Another application of salen ligands is the hydrolytic kinetic resolution of epoxides (Scheme 3). For this purpose cobalt complexes are efficient, and fiu-... 

Choi SD and Kim GJ. Enantioselective hydrolytic kinetic resolution of epoxides catalyzed by chiral Co(III) salten complexes immobilised in the membrane reactor. Catal Lett 2004 92(l-2) 35M-0. 

Liu, Y., Dimare, M., Marchese, S. A., Jacobsen, E. N., Jasmin, S. Hydrolytic kinetic resolution of epoxides using chiral cobalt catalysts. WO 2002-US26729 (2003018520), 2003 (Rhodia/Chirex, Inc., USA). 47 pp... 

The attempt to immobilize a perfluoro-tagged Co(III) salen complex 40 (Fig. 19) on FRPSG did not lead to active catalysts [71]. While complex 40 was active in solution as catalyst for the hydrolytic kinetic resolution of epoxides, the adsorbed complex was inactive. The authors attributed this to site-isolation on the solid support, which counteracts the proposed cooperative reaction mechanism [72,73]. 

This reaction has been extended to occur in ionic liquidj and used for the highly selective hydrolytic kinetic resolution of epoxides. ... 

Hydrolytic kinetic resolution of epoxides Dihydroxylation of C=C Hydroformylation of C=C Hydrosilylation and hydroboration ofC=C... 

Jacobsen s hydrolytic kinetic resolution of epoxides catalyzed by a Co(salen) catalyst analogous to the one used for asymmetric epoxidation has brought a considerable advance to the use of epoxides. Indeed, these substrates are among the most useful reagents in organic synthesis. One of the two epoxide enantiomers is selectively opened by a nucleophile (including water), which leads to both the terminal epoxide and the functional alcohol in quantitative yields (i.e. 50% of each) and more than 98 e.e. for both products. This system has been applied industrially by Rhodia on ton-scales for hydrolysis of propylene oxide and epichlorhydrin. - ... 

Also with starting compounds containing two oxygen nucleophiles, both alkoxy/ amino carbonylation and cyclocarbonylation (carbonylative cydization to lactone) mechanisms can occur in sequence. Some bicydic y-lactones from parasitic wasps (Hymenoptera Braconidae) were synthesized by hydrolytic kinetic resolution of epoxides and palladium(II)-catalyzed hydroxycyclization-carbonylation-lactoniza-tion of enediols. For example, cis- and trans-5-n-hexyl-tetrahydrofuro[3,2-b]furan-2 (3H)-ones 75 and 76, with the (3aR,5R,6aR) and (3aS,5R,6aS) configurations, respectively, were acquired in six steps from the inexpensive, readily available ridnoleic add 74 (Scheme 13.48) (89). 

Paddon-Jones, G.C., McErlean, C.S.P., Hayes, P., Moore, C.J., Konig, W.A. and Kitching, W. (2001) Synthesis and stereochemistry of some bicydic y-lactones from parasitic wasps (Hymenoptera Braconidae). Utility of hydrolytic kinetic resolution of epoxides and palladium(II)-catalyzed hydroxycyclization[Pg.360]

Mateo, C., Archelas, A., Fernandez-Lafuente, R., Guisan, J.M. and Furstoss, R. (2003) Enzymatic transformations. Immobilized A. niger epoxide hydrolase as a novel biocata-lytic tool for repeated-batch hydrolytic kinetic resolution of epoxides. Org. Biomol. Chem., 1,2739-2743. 

Karboune, S., Archelas, A. and Baratti, J. (2006) Properties of epoxide hydrolase from Aspergillus niger for the hydrolytic kinetic resolution of epoxides in pure organic media. Enzyme Microb. Technol., 39, 318-324. 

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