Strain‐Induced Double Carbon–Carbon Bond Activations of Cycloparaphenylenes by a Platinum Complex: Application to the Synthesis of Cyclic Diketones

Abstract The carbon–carbon (C−C) bond activation of [ n ]cycloparaphenylenes ([ n ]CPPs) by a transition‐metal complex is herein reported. The Pt 0 complex Pt(PPh 3 ) 4 regioselectively cleaves two C−C σ bonds of [5] CPP and [6]CPP to give cyclic dinuclear platinum complexes in high yields. Theoretical calculations reveal that the relief of ring strain drives the reaction. The cyclic complex was further transformed into a cyclic diketone by using a CO insertion reaction.