AU-DOUBLEC-H · Gold-catalysed dehydrogenative cross-coupling of arenes

The usually inert carbon-hydrogen (C-H) bond is present in nearly all synthetic and naturally occurring organic molecules. The modification of organic compounds through the direct functionalisation of C-H bonds is however a highly challenging process due to their poor reactivity and the difficulty of discriminating between the many C-H bonds present in most molecules. Nevertheless, catalytic C-H activation has emerged as an increasingly promising strategy for simple and atom-economical cross-coupling of organic compounds. Compared to current methodologies that require the use of pre-functionalized starting materials, the development of general and efficient catalytic C-H activation systems could significantly reduce the amount of waste generated in synthetic reactions by (1) using readily available starting materials (2) shortening reaction sequences and (3) avoiding the stoichiometric generation of metal salts default to synthesis that rely on the use of pre-functionalised building blocks.This project aims at the development of catalytic systems for the formation of biaryls by the direct coupling of two arenes via double C-H activation. Such arylations require the selective breaking of two distinct C-H bonds followed by the subsequent C-C bond formaton. We will make use of the unique ability of gold complexes to discriminate between C-H bonds in different electronic environments depending on the oxidation state of the gold catalyst. Thus, we will develop catalytic cross-coupling processes proceeding via (1) gold(I) mediated C-H activation of electron poor arenes, (2) oxidation of the catalyst to gold(III) followed by gold(III) mediated C-H activation of electron rich arenes, and (3) C-C bond formation furnishing biaryl compounds. The described proposal will significantly contribute to the current state of the art cross-coupling methodologies and offer a direct and green approach to the synthesis of biaryl motifs.