Strategies for the Synthesis of Sulfur-containing Heteroacenes

• Applicant: Professor Dr. Jan Paradies
• Subject Area: Organic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2012 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 228740130

Chemical scientists have been inspired by natural product synthesis to develop highly sophisticated methodologies for organic transformations. Surprisingly, such tendency to develop methodologies for the efficient synthesis of organic materials can only be sparingly observed. However, the development of efficient methodologies for the synthesis of organic materials is of utmost importance. This lack of such synthetic methodology is addressed in the presented project by the efficient synthesis of sulfur-containing heteroacenes by modern transition metal catalysis.Sulfur-based anellated heteroacenes are semi-conductors, which find application in organic field-effect-trasistors (OFET). The access to such structures is often limited by the use of highly toxic and/or moisture- and oxygen-sensitive sulfur reagents. The presented project warrants for the straightforward approach to diversely substituted polyanellated sulfur- and sulfur/nitrogen-containing heteroacenes. This is achieved by a C-S cross coupling/cyclization domino reaction using thiourea as easy and safe to handle sulfur surrogate. Complementary to this strategy is the intramolecular cyclization of diarylthioethers and diarylamines by C-H activation. The intramolecular C-H activation/C-C coupling of bis(thiopene)thioethers or bis(thiophene)amines provides access to bisthienothiophenes and bisthienopyrroles. The modular synthesis of the cyclization precursors warrants for high diversity, thus allowing the modulation of the electronic properties of the systems.Novel heteroacenes will be evaluated in their capabilities to function as semi-conductors in OFET devices.

• DFG Programme: Research Grants