Synthesis of carbonyl-bridged dibenzofulvalenes and related compounds by rhodium-catalyzed stitching reaction.

Various carbonyl-bridged dibenzofulvalenes were synthesized by a sequence of rhodium-catalyzed stitching reaction and post-functionalization, and their optical and electronic properties could be tuned by changing the terminal substituents. The present stitching reaction also allowed for facile synthesis of dibenzofulvalenes having C, Si, Ge, S, and P as the bridging elements.