Iridium-Catalyzed Allylic Substitution with Aromatic andAliphatic Sulfinates

The methodology of enantioselective C-S bond-forming allylic substitution has not been thoroughly developed despite the importance of chiral thioethers, sulfoxides, and sulfones as synthetic building blocks. In particular, only few examples of the allylation of sulfinates leading to branched products A have been reported. The authors describe a highly regio- and enantioselective approach to these compounds using iridium complex 1. A number of products were obtained with high yields (77-99%) and excellent stereoselectivities (86-98% ee). Branched sulfones were predominantly formed (A/B up to >99:1). Iridium-based complexes are well known as the best ­catalysts for allylic rearrangement generating branched heterosubstituted products. This paper describes an important additional example of O/S substitution.