Abstract: The present invention relates to a process for coupling a heterocyclic aromatic ring AR1 and a carbocyclic or heterocyclic aromatic ring AR2 to each other by a light-assisted decarboxylative carbon-carbon cross-coupling reaction, wherein a reaction medium is provided by mixing a first reactant, a second reactant and a catalyst composition, wherein the catalyst composition comprises (i) a palladium compound which is a palladium salt or a palladium complex or a mixture thereof, and (ii) a polycyclic compound of Formula (I), (II) or (III): the reaction medium is irradiated by an external light source, thereby coupling the heterocyclic aromatic ring AR1 of the first reactant to the aromatic ring AR2 of the second reactant by a decarboxylative carbon-carbon cross-coupling reaction.

Abstract: The present invention relates to a catalyst composition for synthesis of heteroaromatic biaryls by a light-assisted decarboxylative carbon-carbon cross-coupling reaction, wherein the composition comprises (i) a palladium compound which is selected from a palladium salt or a palladium complex or a mixture thereof, (ii) at least one of the following compounds: a compound of Formula (I) a compound of Formula (II) an iridium complex comprising ligands L1, L2 and L3, wherein the ligands L1, L2 and L3 are selected, independently from each other, from a phenylpyridine and a bipyridine.

Abstract: The present invention relates to a composition, comprising a palladium compound which is a palladium salt or a palladium complex or a mixture thereof, and a polycyclic compound of Formula (I), (II) or (III):