Butcher TW, Hartwig JF. Enantioselective Synthesis of Tertiary Allylic Fluorides by Iridium-Catalyzed Allylic Fluoroalkylation.
Angew Chem Int Ed Engl 2018;
57:13125-13129. [PMID:
30136379 DOI:
10.1002/anie.201807474]
[Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/17/2018] [Indexed: 12/16/2022]
Abstract
Few allylic electrophiles containing two different substituents at a single allyl terminus and none in which one of the two substituents is a heteroatom, have been shown previously to react with iridium catalysts to form substitution products. We report that iridium-catalysts are uniquely suited to form tertiary allylic fluorides enantioselectively by the addition of a diverse range of carbon-centered nucleophiles at the fluorine-containing terminus of 3-fluoro-substituted allylic esters. The products contain tertiary stereogenic centers bearing a single fluorine, which are isosteric with common tertiary stereocenters containing a single hydrogen. Computational studies reveal the principal steric interactions influencing the stability of endo and exo π-allyl intermediates formed from 3,3-disubstituted allylic electrophiles.
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