Rhodaelectrocatalysis for Annulative C-H Activation: Polycyclic Aromatic Hydrocarbons through Versatile Double Electrocatalysis

Angew Chem Int Ed Engl. 2019 May 6;58(19):6342-6346. doi: 10.1002/anie.201901565. Epub 2019 Apr 1.

Abstract

Rapid access to structurally diversified polycyclic aromatic hydrocarbons (PAHs) in a controlled manner is of key significance in materials sciences. Herein, we describe a strategy featuring two distinct electrocatalytic C-H transformations for the synthesis of novel nonplanar PAHs. The combination of rhodaelectrooxidative C-H activation/[2+2+2] alkyne annulation of easily accessible boronic acids with electrocatalytic cyclodehydrogenation provided modular access to diversely substituted PAHs with electricity as a sustainable oxidant. The unique molecular topology as well as the photophysical and electronic properties of the thus obtained PAHs were fully analyzed. The unique power of this metallaelectrocatalysis method was demonstrated by the chemoselective assembly of synthetically useful iodo-substituted PAHs.

Keywords: C−H activation; dehydrogenation; electrochemistry; polycyclic aromatic hydrocarbons; rhodium.