Synthesis of para-substituted 3-formyl arylboronic esters

The synthesis of novel para-substituted amino- and phenoxy-3-formylarylboronic acids is described. These compounds are formed by the hitherto unreported nucleophilic aromatic substitution of fluorine with a range of phenols and amines in the presence of a boronic acid moiety. These reactions proceed in moderate to good yields (37-92%) and provide a useful regioselective synthetic route to trisubstituted arylboronates. These compounds are important both as intermediates in organic synthesis and as end products in their own right.