Fluorothiazynes, 50 Years Old and Still Exciting: Electrophilic Attack at the Thiazyl Nitrogen of NSF2NS(O)F2

One of the most interesting compounds in sulfur nitrogen fluorine chemistry is NSF2NS(O)F2 (3) (reported by Glemser and Höfer 30 years ago): in the NS backbone a triple and a double bond are connected by a single bond. Electrophiles (metal cations, fluoro Lewis acids, “CH3+”) attack this multifunctional system exclusively at the thiazyl nitrogen of the triple bond. [M(NSF2NS(O)F2)4][AsF6]2 (M=Ni (4b), Cu (4c)), [Re(CO)5(NSF2NS(O)F2)][AsF6]− (5), F5A·NSF2NS(O)F2 (A=As (6), Sb (7)), F3B·NSF2NS(O)F2 (8) and [H3CNSF2NS(O)F2]+[AsF6]− (9) were isolated. The X-ray structures of 4c, 6, 8 and 9 are reported, bonding in these complexes is compared with the recently reported related NSAr2NS(X)Ar2 (X=O, NH) species.