Synthesis of Dithioester Derivatives by Base-Mediated Fragmentation of 1,3-Dithiolanes

Dithioesters are important agents for chain transfer
in polymer
chemistry and precursors in the synthesis of heterocycles. Straightforward
approaches to their synthesis are therefore in demand. Outlined herein
is a method to access such compounds in one-pot. 2-Aryl-1,3-dithiolanes
undergo ring fragmentation with LiHMDS in CPME to generate aryl-dithiocarboxylates
in 5 min at 100 °C. These anions are subsequently captured in
the second step by addition of various alkyl halides and diaryliodonium
salts to furnish a large library of dithioesters in good yields. The
method can be also employed in a one-pot, one-step manner for alkyl
bromides and allows the synthesis of dithioesters in gram scale.