55673-74-0Relevant academic research and scientific papers
Nucleophilic Substitution at Sulphonyl Sulphur.Part 1. Reactivity of Tiophen-2-sulphonyl Halides in Water and Methanol-Acetonitrile
Arcoria, Antonio,Ballistreri, Francesco P.,Musumarra, Giuseppe,Tomaselli, Gaetano A.
, p. 221 - 227 (2007/10/02)
The reactions kinetics of substitued tiophen-2-sulphonyl chlorides and fluorides (5-OMe, 5-Me, H, 5-Cl, 4-NO2, 5-NO2) with anionic and neutral nucleophiles were studied in water at 25 deg C.For the reactions of chlorides with H2O,AcO-,and N3- and for the hydrolysis of fluorides U shaped Hammett plots were observed.For the reaction of sulphonyl chlorides with aniline,pyridine,imidazole,and OH- an approximately linear Hammett correlation is found.Common chloride ion effects on the hyrolysis rate constants appear to be absent.Nucleophilic substitution reactions of substitued thiophen-2-sulphonyl chlorides were also studied in MeOH-MeCN,where the Hammett equation is obeyed.The data appear consistent with an SN2-type mechanism wich can shift toward an SN1 or an SAN process depending on the nucleophile, on the ring substituent, and on the leaving group ability.The application of the More O'Ferrall and Thornton approaches for the prediction of substituent effects on the transition state structure seems to support the above interpretation.
