Iridium-Catalyzed Direct Tetraborylation of Perylene Bisimides

Significance

The class of dyes known as perylene tetracarboxylic acid bisimide (PBI) has received much attention recently due to their interesting electronic and optical properties. PBI derivatives are typically accessed via electrophilic substitution at the 1-, 6-, 7- and 12-positions around the rim of the bay regions. However, not until recently have the 2-, 5-, 8- and 11-positions been functionalized by alkyl- and arylation. Here, the same authors report the direct iridium-catalyzed tetraborylation of PBIs at the 2-, 5-, 8- and 11-positions (1). In addition to serving as a potentially useful synthetic building block, the borylations also allow subsequent introduction of an oxygen heteroatom at these positions.