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 cm2 V−1 s−1, demonstrating that they are useful building blocks for high performance organic semiconductors. [ABSTRACT FROM AUTHOR]