Carbonyl Regeneration by Oxidative Cleavage of 1,3-Dithiolanes and 1,3-Dithianes

Five‐Membered Heterocycles with Two Heteroatoms: O and S Derivatives

“…SOCl 2 -treated silica and DMSO is a good combination with which to cleave 2-substituted-1,3-dithiolanes; however, under similar conditions 2,2-disubstituted-1,3-dithiolanes undergo ring expansion to give dihydro-1,4-dithiins [212]. Recent methods for the cleavage of 1,3-dithiolanes include the use of 2,4,6-trichlorotriazine and DMSO [213], oxone on wet alumina [214] and ferric nitrate on K-10 montmorillonite clay [215].…”

Sulfur and Phosphorus Peroxides

“…When a variety of aldehydes and N,N-dimethylhydrazones are treated with Oxone on wet Al 2 O 3 under microwave irradiation in the absence of a solvent, the corresponding nitriles are obtained in good yields 187 190 . This method is effective for the cleavage of cyclic trimethylene dithioacetal derivatives, which are inert towards the action of a variety of reagents.…”

An Organocatalytic Process for the Hydrolytic Cleavage of Dithianes Mediated by Imidazolium Ions: No Harsh Agents Required

“…A second commonly used method is based on the halogenative cleavage of the dithiane using either N ‐halosuccinimides [e.g., NBS ( N ‐bromosuccinimide)13,14 or NCS ( N ‐chlorosuccinimide)13,15] or hypervalent iodine 16. A variety of other specialised reagents have also proved effective in this deprotection reaction, including Oxone,17 Selectfluor,18 and Clayfen 19. However, many of the aforementioned methods present challenges associated with toxicity or other concerns related to environmental impact, particularly many of the methods based on toxic metal ions (e.g., highly toxic mercury and thallium salts).…”