A catalyst-free method for the synthesis of (Het)ArSF4Cl by using trichloroisocyanuric acid and potassium fluoride in acetonitrile is disclosed.

An eccentric trans-SF4 unit achieves a rod-like linear connection of two independent N-heterocycles, pyridines and triazoles.

A radical addition reaction of Py-SF4Cl to alkynes and alkenes provide pyridine-SF4-alkenes and pyridine-SF4-alkanes under blue LED light irradiation or absence of light irradiation in CPME or without solvent.

Alkyne hydroamination is an effective approach for the production of enamines and enamine‐containing N‐heterocycles. However, stereoselectivity control is a considerable challenge in this reaction because of the electronic repulsion between an incoming nitrogen lone pair and the alkyne π‐system. Herein, we propose a methodology involving β‐regio‐ and Z‐selective alkyne hydroamination by using tetrafluoro‐λ6‐sulfanyl (SF4) alkynes under superbasic, naked anion conditions. The reaction is compatible with a wide variety of N‐heterocycles, including indoles, carbazoles, pyrazoles, and imidazoles, and selectively furnishes SF4‐linked Z‐vinyl enamines with β‐regioselectively. Moreover, the method can be extended to the β‐ and Z‐controlled, base‐mediated alkyne hydrophenoxylation with phenols to provide SF4‐linked Z‐vinyl ethers in high yields. As the SF4 unit has attracted attention as a bioisostere for alkynes, p‐benzenes, bicyclo[1.1.1]pentyl (BCP) groups, and cubanes in medicinal chemistry, this chemistry represents an effective approach to creating novel drug candidates incorporating SF4‐containing molecules.

Fluoro-functionalization is now recognized as a critical strategy in drug discovery; however, the accessible fluoro-functional groups are limited. We herein introduce an eccentric, fully fluorinated motif, trans-tetrafluoro-λ6-sulfanyl gem-difluorocyclopropene 2. This novel motif is highly lipophilic and polarized, enabling a connection of two independent groups via three continuous atoms with a large angle of pseudo cis configuration. The target motif was synthesized via a [2+1] cycloaddition of electron-deficient (hetero)­aryl-SF4-alkynes 1 with an electrophilic difluorocarbene source.