TBAF-catalyzed reaction of a range of substituted epoxides with hexamethyldisilathiane smoothly affords a direct and simple access to b-mercaptoalcohols in a highly regio-and stereoselective way.

Reactions of hexamethyldisilathiane (HMDST) with carbonyl compounds under the catalytic activity of CoCl 2 ·6H 2 O or trimethylsilyltriflate lead to a simple and general access to thioaldehydes and thioketones, which could be isolated as their cycloadducts with dienes. The use of CF 3 SO 3 SiMe 3 in reactions with cyclohexadiene allows a stereopredetermined access to either the endo-or the exo-isomer. Furthermore, on using b-silyl-substituted acetylenic ketones, a smooth access to acetylenic thioketones can be achieved. In reactions with aromatic and heteroaromatic o-azido aldehydes, the reactivity of HMDST may be finely tuned toward the synthesis of o-azido thioaldehydes, fused isothiazole ring systems, aromatic and heteroaromatic o-amino aldehydes, and o-amino thioaldehydes.HMDST proved also very efficient in thionating more intriguing substrates such as acylsilanes. Thus, thioacylsilanes, thioformylsilanes, unsaturated thioacylsilanes and -stannanes can be obtained in good yields. Ethylenic thioacylsilanes showed an interesting behavior leading to a general synthesis of functionalized dithiins. Finally, HMDST led also to the synthesis of bis(thioacylsilanes), which led to the formation of new silylated thiaheterocyclic systems.

A practical and scalable route to the SMO receptor antagonist SEN794 1 is described herein. A new and efficient access to the key intermediate 7 via the Kröhnke reaction was developed, significantly simplifying the synthesis and reducing costs. The optimized route consists of six chemical steps plus a palladium scavenging step. The intermediates are solids and were isolated by filtrations, except for ester 9, which was telescoped as the crude oil into the subsequent step. In the final amide formation step, target compound 1 was conveniently crystallized from the reaction mixture in high purity.

Reaction of stannylated allenes with bis(trimethylsilyl)sulfide/CoCl 2 ·6H 2 O affords the first example of the synthesis of thioacylstannanes. The so obtained thiopropenoylstannanes behave as efficient thiabutadienes towards different in situ generated thioaldehydes and thioacylsilanes, leading to 2-substituted 4-stannyl-1,3-dithiacyclohex-4-ene derivatives through a regioselective hetero Diels-Alder reaction.

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