New Enantiopure Bis-Thioether and Bis-Sulfoxide Ligands from Benzothiophene

The C2-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 PdII complexes. The fused pentacyclic structure of the complexes imparts a rigid chiral environment around the metal centre. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)