TBD-catalyzed α-sulfenylation of cyclic ketones: desymmetrization of 4-substituted cyclohexanones

A low loading of triazabicyclo[4.4.0]dec-5-ene (TBD) catalyzes the α-sulfenylation reaction of ketones employing tetramethylthiuram disulfide (TMTDS) as electrophilic reagent. This methodology is mild, effective and straightforward, rendering the desired products in high yield. Prochiral 4-substituted cyclohexanones can be desymmetrized with remarkable diastereoselectivity following this protocol. The dithiocarbamoyl function was shown to be easily removed upon reduction, affording thiols (1-mercaptan-2-ols).