Gold- and Iodine-Mediated Internal Oxygen Transfer of Nitrone- and Sulfoxide-Functionalized Alkynes
journal contributionposted on 21.10.2011, 00:00 by Dan Chen, Guoyong Song, Aiqun Jia, Xingwei Li
Intramolecular oxygen transfer of nitrone– and sulfoxide–alkynes was achieved using a catalytic amount of Au(I) and a stoichiometric amount of iodine. The Au(I)-catalyzed cyclization of a nitrone–terminal alkyne afforded a cyclic iminoester, while cyclization of analogous nitrone–internal alkynes yielded aldehyde–enones. The I2-mediated cyclization of nitrone–alkynes afforded iodinated γ-lactams and the I2-mediated internal redox of the closely related sulfoxide–alkynes gave diketones functionalized with a thoiether.