Regio- and Stereoselective Synthesis of Highly Functionalized Tetrasubstituted Olefins by Iodine-Mediated Iodofunctionalization of Ferrocene-Containing Allenylphosphonates.

An iodine-mediated iodofunctionalization of ferrocene-containing allenylphosphonates with various carboxylic acids, alcohols, and phenols has been established, affording a series of highly functionalized tetrasubstituted alkenylphosphonate derivatives with high regio- and stereoselectivities in moderate to good yields. This approach provides an opportunity to the useful but not readily available tetrasubstituted olefins. The stereoselectivity of the reaction may be controlled by the neighboring group participation of the oxygen atom of the phosphate group.