Hypervalent Iodine(III)‐Catalysed Enantioselective α‐Acetoxylation of Ketones. Issue 46 (20th July 2020)

• Record Type: Journal Article
• Authors: Hokamp, Tobias; Wirth, Thomas
• Is Part Of: Chemistry. Volume 26:Issue 46(2020)
• Page Start: 10417
• Page End: 10421
• Publication Date: 2020-07-20
• Subjects: α-acetoxylation -- catalysis -- hypervalent iodine -- ketones -- stereochemistry; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202000927
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: An enantioselective catalytic synthesis of α‐acetoxylated ketones through I(I)/I(III) catalysis using a resorcinol/lactamide‐based chiral iodoarene is reported. Catalyst turnover by in situ generation of the active iodine(III) derivative is achieved by oxidation with m CPBA in the presence of acetic acid. The prior transformation of ketones to easily accessible acetyl enol ethers is beneficial and yields up to 97 % with enantioselectivities up to 88 % ee are obtained using only low catalyst loadings of only 5 mol % under mild reaction conditions. Abstract : An efficient and easy acetoxylation of ketones via their enolethers is described. With low catalyst loadings of a chiral aryliodine high stereoselectivities can be obtained under mild reaction conditions.