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Thioacylsilanes containing the ferrocene moiety, easily prepared from the corresponding acylsilanes with Lawesson's reagent at room temperature, can be transformed into vinyl silanes, sulfur heterocycles and sulfines.

The allylation of acylsilanes with tetraallyltin in the presence of catalytic amounts of Sc(OTf) 3 proceeded smoothly to afford the silylated homoallylic alcohols in good yields. Subsequent protiodesilylation gave the formal adducts of the corresponding aldehydes. The homochiral acylsilane 11 gave a reversal of asymmetric induction in the Sc(OTf) 3 catalyzed allylation and in the Sakurai reaction.

Reaction of dithioesters and trithiocarbonates with silylated nucleophiles under fluoride ion conditions affords a novel example of silyl mediated regiochemical control in the thiophilic functionalization.

Intramolecular cyclization of enethiolizable (allylthio)sulfines afford 2-alkylidene-1,3-dithiolane-1-oxides in good yields. The formation of these compounds can be explained by an initial tautomerization of the sulfine to vinyl sulfenic acid, followed by an intramolecular addition of the sulfenic acid to the allylic double bond. The stractures of the products were elucidated by means of 1H-and 13C-NMR spectroscopy as well as LIS effects, deuteriation experiments and an X-ray analysis.

The reaction of acylsilanes 1 with Grignard reagents gives the diastereomeric α-hydroxysilanes 3 . The level of asymmetric induction depends on the nature of R 1 and R 2 . Good results were obtained for R 1 =t-Bu, R 2 =Me and R 1 =α-Napht, R 2 =Ph. Subsequent desilylation occurs with predominant inversion of configuration at carbon.

4H-1,3-Oxathiins are obtained by an high yield heterocycloaddition of thiones with vinyltrimethylsilylketone, behaving as heterodiene. 4H-1,3 Oxathiins can be oxidized to the corresponding S-oxides, which are the formal cycloadducts of sulphines.

Desilylation of either α-silyl sulphides or silyl dihydrothiopyrans (easily obtained from silyl thiones as primary adducts), when performed in the presence of carbon electrophiles (aldehydes or ketones), offers an easy entry to carbofunctionalised products.

The reaction of organolithium compounds with stilbene episulphoxides and episulphides leads to stereospecific desulphurization and to ring opening. The stereochemistry of the latter reaction depends on the structural features.

Dyaryl-, dialkyl-, and aryltriphenylsilyl- thioketones have been shown to efficiently scavenge thiyl, sulphonyl and selenyl radicals affording adducts identified by ESR spectroscopy. Unprecedented evidence of the trapping of t BuO· radicals by thiones has also been obtained.

Conjugated nitrosoalkenes, generated in situ via dehydrobromination of α-bromoketoximes, undergo an easy [4+2]-cycloaddition with thiocarbonyl compounds to give very high yields of the new heterocycles 4H-1,5,2-oxathiazines. The thermolysis and the behaviour to oxidation of these adducts were tested.

Silylated thiirans upon oxidation with peroxyacids do not give exclusively the corresponding S-oxides but, in addition some products derived from ring opening. The stereochemistry of the oxidation to thiiran-1-oxides is anti to the silyl group as demonstrated by X-ray analysis.

The reaction of R-(-)-methyl-α-naphtyl-phenylsilyl phenyl thioketone 1 with organolithium derivatives and Grignard reagents gives the α-silylsulphides 3 with medium to good levels of asymmetric induction. The asymmetry induced at the α-carbon is retained in the subsequent desilylation.

Pyridine N-oxides are deoxygenated by sulphur monoxide. Electron withdrawing substituents lower drastically the yields of reduction.