Transition metal-catalyzed cross-coupling methodologies for the engineering of small molecules with applications in organic electronics and photovoltaics

Cross-coupling reactions have played a key role in producing numerous types of ?-conjugated small molecules having appealing properties for practical applications in organic electronics, especially in the field of photovoltaics. The main advantages of such synthetic methodology are the compatibility with many types of functional groups and the flexibility which allows an easy way to introduce diversity and tune the electronic and photophysical properties of the target molecules. As a result, many semiconducting and photoactive organic compounds have been synthesized using this powerful tool. In this paper we will highlight a number of selected syntheses and optimized C-C bond formation processes described in the years 2000-2018 and related to this specific field, choosing those examples which can demonstrate the enormous power of the cross-coupling processes, but also the room for improvements of these methodologies.