Cationic palladium(II)-catalyzed synthesis of 2-substituted 3-hydroxymethylbenzo[b]furans was written by Wang, Huan;Han, Xiuling;Lu, Xiyan. And the article was included in Synlett in 2011.Electric Literature of C6H4BrIO This article mentions the following:
A tandem reaction involving an intramol. oxypalladation of an alkyne and an addition to the carbonyl group to quench the carbon-palladium bond to complete the catalytic cycle was developed. The reaction of 2-alkynylphenols with aldehydes to prepare substituted 3-(hydroxymethyl)benzofurans in one pot is described. E.g, reaction of 2-(phenylethynyl)phenol and p-nitrobenzaldehyde, catalyzed by [Pd(dppp)(H2O)2](BF4)2, gave 90% benzofuran (I). The reaction was catalyzed with the cationic palladium(II) species without the necessity of a redox system. In the experiment, the researchers used many compounds, for example, 4-Bromo-2-iodophenol (cas: 207115-22-8Electric Literature of C6H4BrIO).
4-Bromo-2-iodophenol (cas: 207115-22-8) belongs to iodide derivatives. Organic iodides can be alkyl, alkenyl, or alkynyl, and all of them are very reactive toward with many kinds of nucleophiles. The C–I bond is the weakest of the carbon–halogen bonds. These bond strengths correlate with the electronegativity of the halogen, decreasing in the order F > Cl > Br > I. This periodic order also follows the atomic radius of halogens and the length of the carbon-halogen bond.Electric Literature of C6H4BrIO
Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com