Synthesis and characterization of symmetric cyclooctatetraindoles: exploring the potential as electron-rich skeletons with extended π-systems.

A facile one-pot tetramerization of indolin-2-one with phosphoryl chloride was applied for the first convenient direct synthesis of C2v-symmetric cyclooctatetraindole with an 8π annulene as the center. Tetra- and octa-arylated cyclooctatetraindole derivatives functionalized with fluorescent fluorene and pyrene units were thus facilely synthesized and characterized.