Disulfoxides, chiral

Owing to its conceptual simplicity and manifest utility, the direct liquid chromatographic separation of enantiomeric sulfoxides on chiral columns has also been attempted. Thus, Montanari et al. (32) found that racemic unsaturated vinyl disulfoxides 23 may be par-... 

It was also found that the Padua reagent was useful for the oxidation of three isomeric bis(methylsulfmyl)benzenes with r-BuOOH, yielding the corresponding almost enantiopure bis-sulfoxides [64]. As mentioned above, the enantioselectivity of the first oxidation was enhanced (Horeau principle), because a minor amount of meso-disulfoxide was formed and separated from the chiral disulfoxide. It was reported that the Orsay reagent with cumyl hydroperoxide oxidized an /V-protected 2-.S -methylindole with moderate enantioselectivity, whereas the Padua protocol afforded the desired sulfoxide with 80% ee [65],... 

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). 

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