The direct pyrrolidine-catalyzed α-sulfenylation of
aldehydes and ketones with the commercially available, very cheap chemical
tetramethylthiuram disulfide (thiram) is described. The dithiocarbamoyl
derivatives are obtained in good to excellent yields (47-98%).
In the case of α-substituted aldehydes the protocol allows
the generation of quaternary stereocenters. The sensibility of the α-sulfenylated
carbonyl compounds for racemization has been investigated.
organocatalysis - thiram - sulfenylation - dithiocarbamate - enamine