Organosilanes-Mediated Synthesis and Reactivity of Thiocarbonyl-Containing Molecules

Abstract:

The reaction of hexamethyldisilathiane (HMDST) with different carbonyl compounds affords, under the catalysis of CoCl₂.6H₂O or CF₃SO₃SiMe₃ a general access to several thioaldehydes and thioketones including acetylenic derivatives and thioformylsilanes. The use of CF₃SO₃SiMe₃ allows a stereopredetermined entry to both the endo or the exo isomers when cyclohexadiene is used as the trapping agent. Furthermore, when using aromatic and heteroaromatic o-azidoaldehydes, the reactional behavior of HMDST may well be finely tuned to drive the reaction toward the synthesis of o-azidothioaldehydes, fused isothiazole ring systems, aromatic and heteroaromatic o-aminoaldehydes and o-amino thioaldehydes. Finally, taking advantage of the high reactivity of the C-Si bond under fluoride ion catalysis, a selective regiospecific thiophilic functionalization of thioketones, dithioesters, trithiocarbonates and their sulfines by different organosilanes can be obtained.