Isocyanatosulfonium‐Salze

Isocyanatosulfonium Salts RR'SF 2 reacts with Me 3 SiNCO to give the corresponding N ‐(fluoroformyl)sulfur imides FC(O)NSRR' [R = NMe 2 , R' = F ( 7 ); R' = CF 3 ( 9 )]. From these AsF 5 abstracts F ‐ with formation of isocyanatosulfonium salts ONC—SRR' + AsF ‐ 6 [R = F, R' = CF 3 ( 6 ); R = NMe 2 , R' = F ( 8 ); R = NMe 2 , R' = CF 3 ( 10 )]. The spectroscopic properties of the fluoroformyl derivatives and of the isocyanato salts are discussed. The structures of 8 and 10 are determined by X‐ray analyses.