New Synthetic Approaches to N ‐Aryl and π‐Expanded Diketopyrrolopyrroles as New Building Blocks for Organic Optoelectronic Materials

Diketopyrrolopyrrole (DPP) as a building block has been intensively investigated for organic semiconductors and light emitting materials. The synthesis of N ‐aryl DPPs remains challenging. Herein, we firstly report a new easily handled synthetic method toward N ‐aryl DPPs through H‐DPP with diaryliodonium salt in the presence of CuI, which shows broad reaction scope. Sixteen N ‐aryl DPPs, including phenyl, furan and thiophene as flanking aromatic groups, were synthesized with yields up to 78 %. These N ‐aryl DPPs are fluorescent in both solutions and solid states, with quantum yields up to 96 % and 40 %, respectively. Moreover, we show that the reaction between H‐DPP and diaryliodonium salt can lead to π‐expanded DPPs by using Pd(OAc) 2 as catalyst. Nine π‐expanded DPPs were obtained in 27–61 % yields. These π‐expanded DPPs exhibit good semiconducting properties with hole mobility of 0.71 cm 2  V −1  s −1 , demonstrating that they are useful building blocks for high performance organic semiconductors.