Synthesis of fully asymmetric diketopyrrolopyrrole derivatives

Abstract

Diaryl-diketopyrrolopyrroles (DPP) are a widely studied class of chromophore that possesses unique properties which have been of great interest for use in conjugated polymers and as small molecules in optoelectronic devices. While previously only partially asymmetric DPP derivatives have been reported, here a novel methodology towards fully asymmetric DPP derivatives is demonstrated via the synthesis and condensation of novel alkylated thienyl pyrrolinone esters with aromatic nitriles followed by N-alkylation. Two fully asymmetric DPP structural isomers T-DPP-P and P-DPP-T were synthesised demonstrating the full customizability of the DPP core. A further two fully asymmetric DPP derivatives incorporating an ethylene glycol chain and a furan moiety were also synthesised, demonstrating the scope of this powerful methodology and it's potential to largely broaden the library of available DPP derivatives.