Mitra S, Sarkar R, Chakrabarty A, Mukherjee S. Hydroxy-directed iridium-catalyzed enantioselective formal β-C(sp
2)-H allylic alkylation of α,β-unsaturated carbonyls.
Chem Sci 2022;
13:12491-12497. [PMID:
36382287 PMCID:
PMC9629034 DOI:
10.1039/d2sc03966d]
[Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 10/12/2022] [Indexed: 02/12/2024] Open
Abstract
Hydroxy-directed iridium-catalyzed enantioselective formal β-C(sp2)-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.
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