Methods for asymmetric e poxidation using flow reactors
AssigneeCorning Incorporated
InventorPatrick Rosaire Bazinet
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Abstract
Embodiments of the present disclosure relate to asymmetric epoxidation of olefinic alcohols, using a chiral alcohol chelated titanium catalyst and an organic peroxide performed in a microreactor flow reactor system that can comprise multiple microreactor modules. Molecular sieves can be used to remove any adventitious water in the reagent feed solutions and ensure an anhydrous reaction solution. The use of a microreactor flow reactor allows for the epoxidation reaction to be run at elevated temperatures of at least 20, 30, or even 50° C., which dramatically accelerates the reaction, but without a large drop in enantioselectivity. The reaction can therefore be performed with short reaction times resulting in a high throughput.
Claims15
A method of performing asymmetric epoxidation of olefinic alcohols, the method comprising:
- providing a flow reactor including thermal control having channels with a sub-millimeter to multiple-millimeter scale cross section;
- generating a chiral-alcohol chelated transition metal catalyst within the flow reactor and mixing the chiral-alcohol chelated transition metal catalyst with an olefinic alcohol within the flow reactor, forming a first mixture comprising the chiral-alcohol chelated transition metal catalyst and the olefinic alcohol;
- epoxidizing the olefinic alchohol by flowing a stoichometerically excess amount of an organic hydroperoxide into the flow reactor and mixing the organic hydroperoxide with the first mixture, forming a second mixture comprising the chiral-alcohol chelated transition metal catalyst, the partly or wholly epoxidized olefinic alcohol and the remaining organic hydroperoxide;
- and
- quenching the second mixture by flowing a reducing agent into the flow reactor and mixing the reducing agent with the second mixture,
- wherein the epoxidation step is performed within a temperature-controlled portion of the flow reactor at a temperature of at least 20° C. and within a time of 4 minutes or less, with an epoxide yield of at least 82% and an enantioselectivity of at least 85%.
Dependencies are inferred from the claim text.