Disulfoxide ligands

In addition, several S/S ligands were also investigated for the asymmetric hydrogenation of olefins. In 1977, James and McMillan reported the synthesis of various disulfoxide ligands, which were applied to the asymmetric ruthenium-catalysed hydrogenation of prochiral olefinic acid derivatives, such as itaconic acid. These ligands, depicted in Scheme 8.16, were active to provide... 

Scheme 8.16 Hydrogenation of itaconic acid with disulfoxide ligands.

Liao and coworkers [49], in 2011, reported the synthesis of a new family of benzene-based chiral hetero-disulfoxide ligands and applied them successfully in the Rh-catalyzed asymmetric 1,4-addition of arylboronic adds to chromenones. The application of the Hayashi-Miyaura reaction on these substrate types is without a doubt a milestone in the development of this process, as the synthesis of enantiopure flavanones is a significantly challenging undertaking. With this procedure, the authors achieved the desired addition products in up to 70% yield and up to 95% ee (Scheme 5.12). 

Since chalcogen groups are also potential redox-active sites, we have studied the coordination polymers constructed by bridging ligands with chalcogen sites. For the syntheses of coordination polymers with sulfide and disulfoxide sites, 4-pyridylthioacetate (pyta), 4,4 -sulfonyldibenzoate... 

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