Gold- and Iodine-Mediated Internal Oxygen Transfer of Nitrone- and Sulfoxide-Functionalized Alkynes
摘要:
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 I-2-mediated cyclization of nitrone-alkynes afforded iodinated gamma-lactams and the I-2-mediated internal redox of the closely related sulfoxide alkynes gave diketones functionalized with a thoiether.