Asymmetric Chemoenzymatic Reductive Acylation of Ketones by a Combined Iron‐Catalyzed Hydrogenation–Racemization and Enzymatic Resolution Cascade. Issue 8 (24th March 2017)

• Record Type: Journal Article
• Authors: El‐Sepelgy, Osama; Brzozowska, Aleksandra; Rueping, Magnus
• Is Part Of: ChemSusChem. Volume 10:Issue 8(2017)
• Page Start: 1664
• Page End: 1668
• Publication Date: 2017-03-24
• Subjects: cascade catalysis -- chiral alcohols -- enzyme -- kinetic resolution -- racemization; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201700169
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: A general and practical process for the conversion of prochiral ketones into the corresponding chiral acetates has been realized. An iron carbonyl complex is reported to catalyze the hydrogenation–dehydrogenation–hydrogenation of prochiral ketones. By merging the iron‐catalyzed redox reactions with enantioselective enzymatic acylations a wide range of benzylic, aliphatic and (hetero)aromatic ketones, as well as diketones, were reductively acylated. The corresponding products were isolated with high yields and enantioselectivities. The use of an iron catalyst together with molecular hydrogen as the hydrogen donor and readily available ethyl acetate as acyl donor make this cascade process highly interesting in terms of both economic value and environmental credentials. Abstract : An inexpensive iron carbonyl complex catalyzes the hydrogenation of ketones and the subsequent racemization of the resulting alcohols. The iron‐catalyzed redox reactions were combined with lipase‐catalyzed enantioselective acylation of the formed alcohol. This cooperative catalytic system was applied in the asymmetric reductive acylation of different prochiral ketones by a hydrogenation/dynamic kinetic resolution cascade.