A One‐Pot Cascade Reaction Combining an Encapsulated Decarboxylase with a Metathesis Catalyst for the Synthesis of Bio‐Based Antioxidants. Issue 47 (18th October 2016)

• Record Type: Journal Article
• Authors: Gómez Baraibar, Álvaro; Reichert, Dennis; Mügge, Carolin; Seger, Svenja; Gröger, Harald; Kourist, Robert
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 47(2016)
• Page Start: 14823
• Page End: 14827
• Publication Date: 2016-10-18
• Subjects: bio-based antioxidants -- biocatalysis -- compartmentalization -- decarboxylation -- metathesis; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201607777
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The combination of enzymes with traditional chemical catalysts unifies the high selectivity of the former with the versatility of the latter. A major challenge of this approach is the difference in the optimal reaction conditions for each catalyst type. In this work, we combined a cofactor‐free decarboxylase with a ruthenium metathesis catalyst to produce high‐value antioxidants from bio‐based precursors. As suitable ruthenium catalysts did not show satisfactory activity under aqueous conditions, the reaction required the use of an organic solvent, which in turn significantly reduced enzyme activity. Upon encapsulation of the decarboxylase in a cryogel, the decarboxylation could be conducted in an organic solvent, and the recovery of the enzyme after the reaction was facilitated. After an intermediate drying step, the subsequent metathesis in pure organic solvent proved to be straightforward. The synthetic utility of the cascade was demonstrated by the synthesis of the antioxidant 4, 4′‐dihydroxystilbene in an overall yield of 90 %. Abstract : The mutual incompatibility of catalysts and their reaction conditions is a frequent challenge for chemoenzymatic one‐pot reactions. The encapsulation of a decarboxylase in PVA/PEG gel capsules enabled its combination with a ruthenium metathesis catalyst in organic solvents for the synthesis of antioxidants from inexpensive, bio‐based hydroxycinnamic acids in up to 90 % yield.