S,O-Ligand-Promoted Pd-Catalyzed C-H Olefination of Thiophenes

摘要

An efficient PdII catalyzed C-H olefination of thiophenes has been developed using an easily accessible bidentate S,O-ligand. The catalytic system promotes the C-2 olefination of a wide range of thiophenes bearing both, electron donating and withdrawing groups under mild conditions. This methodology provides a direct path towards the synthesis of 2,3-disubstituted thiophenes, which are difficult to obtain via other C-H functionalization routes. The S,O-ligand is responsible for the broad substrate scope and high levels of C-2 selectivity in 3-substituted thiophenes.