Convenient Procedure for the Syntheses of Vinyl Iodides Via the Reaction of Iodine Monochloride with Vinylboronic Acids

摘要

Vinyl halides are important synthetic intermediates. One route to vinyl halides involves the reaction of vinylboronic acids with halogens in the presence of sodium hydroxide. Although the reaction of iodine with organoborane reagents has been carefully investigated and is known to produce good yields of stereochemically defined products, it does have two potential disadvantages. The first is the necessity of using a strong base which could react with sensitive functional groups. The second is the fact that one-half of the iodine molecule is lost as iodide which is not economical when radionuclides of iodine are employed. An alternative method of preparing vinyl halides is reported in this paper. Vinyl boronic acids (readily prepared via the hydroboration of alkynes) react with iodine monochloride to yield the corresponding vinyl iodides. This reaction is applicable to a variety of functionally substituted materials. The reaction of triphenylborane with iodine monochloride is also reported. (ERA citation 06:011336)