Silyl Chloroalkenyl and Alkynyl Sulfur Pentafluorides as versatile reagents to access novel fundamental SF5 building blocks

We recently highlighted the value of silylated SF5 alkynes to access a variety of fundamental SF5 containing building blocks. Herein, we report a solution to the previously reported synthetic bottleneck as well as identified (E)-(1-chloro-2-pentafluoro-6-sulfaneyl)-vinyl)triethylsilane as a second generation platform chemical. This versatile platform reagent is thermally stable, easy to handle, shows high shelf-stability, can be accessed on multi-gram scale and grants facile benchtop access to a variety of fundamental known and unknown SF5-containing building blocks under very mild conditions. In this work we investigated its nucleophilic substitution by S- and N-nucleophiles. The reagent can be activated selectively allowing access to (E)-configured enamines (up to >99% yield), the first synthetically useful access to (E)-configured -vinyl sulfides (up to 99%) and S,S-acetals (up to 97%) in a single reaction step. Further processing allowed convertion into S,S-ketene acetals (up to 90%), which can be hydrolyzed to yield the corresponding esters (up to 88%) as well as -SF5 acetic acid (>99%). Furthermore, we addressed the previous accessibility restrictions on triisopropyl silyl acetylene sulfur pentafluoride (TASP) the development of a novel in-situ elimination strategy and identified the TBDMS derivative of TASP as an accessible, stable and reactive reagent to prepare the complementary (Z)-configured -vinyl sulfides (up to 71%) in a single reaction step.