Bicyclo[1.1.1]pentanes (BCPs) gained interest in material sciences and as non-classical bioisosteres for para-substituted benzenes, alkynes and tert-butyl groups in drug design. The synthesis of BCPs is still challenging and limits their application. Starting from the strained [1.1.1]propellane there have been many contributions using CC and CN bond formations to obtain BCPs. The CS bond formation has been rarely used and not systematically investigated. Therefore, this thesis aimed at the development of methods to obtain BCP sulfides and related structures from [1.1.1]propellane. The obtained BCP sulfides were oxidized and iminated to obtain BCP sulfoxides and sulfoximines. These modifications to tune parameters like the polarity are important for a successful application of the structural motif in drug design. The final aim of this thesis was the synthesis and application of a bench-stable BCP building block to facilitate the use in medicinal chemistry and other fields. A facile and scalable four-step route to sodium BCP sulfinate was developed to deliver the product in good yield and purity. The sulfinate was applied in the synthesis of BCP sulfones, sulfoxides, a sulfinamide and sulfonamides.