Copper(I) Iodide Mediated Iodocyclization of Cyclopropylideneallenyl Ketones: Facile and Effective Synthesis of Highly Substituted Furan Derivatives
作者:Maozhong Miao、Xin Xu、Lijun Xu、Hongjun Ren
DOI:10.1002/ejoc.201402823
日期:2014.9
Electrophilic cyclization of cyclopropylideneallenyl ketones in the presence of I2/CuI offers an efficient and straightforward route to highly substituted furans under mild reaction conditions. Further transformation of the resulting iodofurans provides structurally more advanced furanderivatives.
CuCl-catalyzed cyclization–dimerization reactions of 3-cyclopropylideneprop-2-en-1-ones provide an interesting route to benzofuran-7(3aH)-one derivatives with one highly strained three-membered ring and one four-membered ring via intramolecular cycloisomerization, sequential bimolecular [4 + 2] cycloaddition, opening of the oxa-bridge, and ring contraction. Furthermore, the reaction was monitored by NMR experiments
A novel PdCl2-catalyzed oxidative cycloisomerization of 3-cyclopropylideneprop-2-en-1-ones, providing a facile synthesis of highly strained functionalized 2-alkylidenecyclobutanones via furan-fused cyclobutene intermediates, is reported. An interesting route to 2(3H)-furanones with a spiro-cyclopropane unit from the obtained 2-alkylidenecyclobutanones via a ring-contraction rearrangement reaction is