Influence of superstrong electronaccepting substituent CF3S(O)NSO2CF3 on nucleophilic substitution reactions in aromatic ring

Abstract The CF 3 S(O)NSO 2 CF 3 group is a superstrong electronaccepting substituent. With its σ p value 1,40 it is approximately equal to electronic influance of two nitro groups placed at ortho- and para-positions. Comparing reactivity of 1 and 2 with different nucleophiles has been studied. As it has turned out reactivity of 1 and 2 with CH 3 OH and CF 3 CH 2 OH in the presence of KHCO 3 are approximately equal. But with N 3 − and p-O 2 NC 6 H 4 NH 2 the 1 is not as strong as 2 and with anion I − the former does not react at all under conditions when 2 quantitatively converts to picryl iodide. According to the relative mobility of chlorine in 1 and 2 (1/2) nucleophilic reagents settle down in the following order: I − (0) 2 NC 6 H 4 NH 2 (0,13) 3 CH 2 O − (1) 3 O − (1,32), which indicates that CF 3 S(O)NSO 2 CF 3 group creats a hard reaction centre in contrast to the soft centre in case of nitro groups only. The high electron-accepting power of CF 3 S(O)NSO 2 CF 3 is also evidenced by the fact that chlorine in 1 is substituted quantitatively by PhNH 2 and CF 3 CH 2 O − whereas in 3 under the same conditions — only to 10%.