Epibromohydrin, kinetic resolution

The same immobilized catalyst 36 [69] was also effectively used for dynamie hydrolytic kinetic resolution of epibromohydrin. Five reaction cycles performed with single eatalyst bateh provided combined yield of 94% with 96% ee and in 90% ehemieal purity for the product l-bromo-2,3-propandiol (Scheme 14). 

Scheme 14. Dynamic kinetic resolution of epibromohydrin with polymer bound catalyst 36.

A salen-cobalt complex has been appended to the PASSflow monolith system to form catalyst 42 and used for the dynamic kinetic resolution of epibromohydrin, 43. Because 43 undergoes rapid racemization under the conditions used, all the starting materials can theoretically be converted to the desired diol 44 (Scheme 4.75). The... 

Silica bound chiral Co-salen complex (36) was synthesized and adapted to a continuous-flow reaction. The optical kinetic resolution of racemic epoxide (38) was successful to yield the desired triol (39) in good yield (36% conversion) and high enantiomeric excess (Scheme 7.31) [127]. A PASSflow microreactor consisting of Co-salen monolith (37) was used for the dynamic kinetic resolution of epibromohydrin (40). Three runs performed on the 1-mmol scale were completed and afforded (J )-(41) in 76-87% yield with constant enantiomeric purity of 91-93% ee [128]. 

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