Photoredox‐Mediated Deoxygenative Radical Additions of Aromatic Acids to Vinyl Boronic Esters and gem‐Diborylalkenes. Issue 3 (24th November 2022)

• Record Type: Journal Article
• Authors: Nagaraju, Anugula; Saiaede, Tamer; Eghbarieh, Nadim; Masarwa, Ahmad
• Is Part Of: Chemistry. Volume 29:Issue 3(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-24
• Subjects: carboxylic-acids -- deoxygenation -- gem-diborylalkenes -- organoborones -- photochemistry; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202202646
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A new method to access β‐keto‐ gem ‐diborylalkanes, by direct deoxygenative radical addition of aromatic carboxylic acids to gem ‐dibortlalkenes, is described. The reaction proceeds under mild photoredox catalysis and involves the photochemical C−O bond activation of aromatic carboxylic acids in the presence of PPh3 . It generates an acyl radical, which further undergoes an additional reaction with gem ‐diborylalkenes to form an α‐ gem‐ diboryl alkyl radical intermediate, which then reduces to the corresponding anion, which after protonation, affords the β‐keto‐ gem ‐diborylalkane product. Moreover, the same scenario has been extended to the vinyl boronic esters, for example, gem ‐(Ar, Bpin)‐alkenes, and gem ‐(Alkyl, Bpin)‐alkenes. Importantly, this protocol provides a general platform for the late‐stage functionalization of bio‐active and drug molecules containing a carboxylic acid group. Abstract : Photoredox‐mediate deoxygenation : In this work, we explore an efficient, general photoredox‐mediated deoxygenated approach of abundant, simple, and commercially available carboxylic acids and vinyl boronic esters, which form the important β‐keto‐borylalkanes. Additionally, a protocol of the late‐stage functionalization of naturally occurring bioactive carboxylic acids and drugs has been developed using this approach.