Abstract The C 2-symmetric compound 2, 3, 2, 3-tetrahydro-2, 2-bi (benzo [b] thiophenyl) and three diastereomeric bis (oxide) derivatives can be synthesized in a few steps from benzo [b]-thiophene by oxidative homocoupling of (R)-2, 3-dihydro-benzo [b] thiophene 1- oxide. This new family of enantiopure bis (thioether) and bis (sulfoxide) ligands forms stable chelating Pd II complexes. The fused pentacyclic structure of the complexes imparts a rigid ...