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 pi-expanded DPPs by using Pd(OAc)(2) as catalyst. Nine pi-expanded DPPs were obtained in 27-61 % yields. These pi-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.

Automated summary

The study introduces a new method for synthesizing N-aryl DPPs and expanded π-system DPPs with high yields, which exhibit good fluorescent and semiconductor properties. The synthesized DPPs are promising building blocks for high-performance organic semiconductors.