Synthesis of 9,9-Disubstituted Fluorenes from 2-Iodobiphenyls and α-Diazoesters under Palladium Catalysis.

9,9-Disubstituted fluorenes are widely employed in materials science. We have developed a straightforward approach for the synthesis of 9,9-disubstituted fluorenes from 2-iodobiphenyls and α-diazoesters. The reaction proceeds via a tandem palladium-catalyzed C(sp2)-H activation/carbenoid insertion sequence.