Article

ChemInform Abstract: Intramolecular Aryne-Ene Reaction: Synthetic and Mechanistic Studies.

Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
Journal of the American Chemical Society (Impact Factor: 11.44). 08/2011; 133(36):14200-3. DOI: 10.1021/ja205405n
Source: PubMed

ABSTRACT Although the chemistry of arynes is well developed, some challenges still remain. The ene reaction of arynes has not gained widespread use in synthesis as a result of poor yields and selectivity. A general, high yielding and selective intramolecular aryne-ene reaction is described providing various benzofused carbo- and heterocycles. Mechanistic data is presented, and a rationale for the resulting stereochemistry is discussed.

0 Followers
 · 
193 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Several o-(trimethylsilyl)aryl imidazolylsulfonates were synthesized in a simple process and successfully applied in cycloadditions involving benzyne intermediates. The precursor offers an efficient alternative for generating benzynes compared to widely used ortho TMS triflates under similar reaction conditions. With the utilization of this new precursor, the formation of potentially genotoxic trifluoromethanesulfonate side product is eliminated. The applicability of the new benzyne precursor was demonstrated in different types of cycloaddition reactions to prepare heterocyclic molecules.
    Organic Letters 04/2012; 14(8):2022-5. DOI:10.1021/ol300529j · 6.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A S-O bond insertion reaction of sulfoxides with arynes is reported. This reaction represents a rare instance of semipolar single bond insertion in aryne chemistry. The study of mechanism indicates that a sulfur ylide triggered by aryne is the key intermediate, which further transfers its methylene group to carbonyl compounds to give epoxides and thioethers through a sequential process.
    Organic Letters 02/2015; DOI:10.1021/ol5036326 · 6.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The biosynthetic pathways to isoprenoid compounds involve transfer of the prenyl moiety in allylic diphosphates to electron-rich (nucleophilic) acceptors. The acceptors can be many types of nucleophiles, while the allylic diphosphates only differ in the number of isoprene units and stereochemistry of the double bonds in the hydrocarbon moieties. Because of the wide range of nucleophilicities of naturally occurring acceptors, the mechanism for prenyltransfer reactions may be dissociative or associative with early to late transition states. We have measured delta-secondary kinetic isotope effects operating through four bonds for substitution reactions with dimethylallyl derivatives bearing deuterated methyl groups at the distal (C3) carbon atom in the double bond under dissociative and associative conditions. Computational studies with density functional theory indicate that the magnitudes of the isotope effects correlate with extent of bond formation between the allylic moiety and the electron-rich acceptor in the transition state for alkylation and provide insights into the structures of the transition states for associative and dissociative alkylation reactions.
    The Journal of Organic Chemistry 03/2014; 79(8). DOI:10.1021/jo500394u · 4.64 Impact Factor

Preview

Download
9 Downloads
Available from