Hydroxy-directed iridium-catalyzed enantioselective formal β-C(sp2)–H allylic alkylation of α, β-unsaturated carbonyls. Issue 42 (19th October 2022)

• Record Type: Journal Article
• Authors: Mitra, Sankash; Sarkar, Rahul; Chakrabarty, Aditya; Mukherjee, Santanu
• Is Part Of: Chemical science. Volume 13:Issue 42(2022)
• Page Start: 12491
• Page End: 12497
• Publication Date: 2022-10-19
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2sc03966d
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : The first formal enantioselective β-C(sp 2 )–H allylic alkylation of α, β-unsaturated carbonyls is developed through hydroxy-directed reaction of α-hydroxy enones with racemic branched allylic alcohols under cooperative Ir(i ) and Lewis acid catalysis. Abstract : Hydroxy-directed iridium-catalyzed enantioselective formal β-C(sp 2 )–H allylic alkylation of kojic acid and structurally related α, β-unsaturated carbonyl compounds is developed. This reaction, catalyzed by an Ir(i )/( P, olefin) complex, utilizes the nucleophilic character of α-hydroxy α, β-unsaturated carbonyls, to introduce an allyl group at its β-position in a branched-selective manner in good to excellent yield with uniformly high enantioselectivity (up to >99.9 : 0.1 er). To the best of our knowledge, this report represents the first example of the use of kojic acid in a transition metal catalyzed highly enantioselective transformation.