Aminolysis of aryl dithio-2-thiophenates and dithio-2-furoates in acetonitrile

✍ Scribed by Hyuck Keun Oh; So Young Woo; Chul Ho Shin; Ikchoon Lee

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 167 KB
• Volume: 30
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/(sici)1097-4601(1998)30:11<849::aid-kin7>3.0.co;2-v

✦ Synopsis

The aminolyses of the title substrates with anilines and benzylamines are investigated in acetonitrile. A clean second-order kinetics is obtained with a first-order rate law in the amine concentration, which is uncomplicated by the fast proton transfer step. The large magnitude of as well as together with relatively large positive values is (

consistent with a stepwise mechanism in which thiophenolate ion expulsion from the intermediate is rate limiting. For the reactions of aryl dithio-2-thiophenates with benzylamines the magnitude of and values is relatively smaller suggesting that both the addition and X Z expulsion of thiophenolate are partially rate determining. Relatively large secondary kinetic isotope effects, with deuterated nucleophiles, support involvement a concurrent k /k Ն 1.7, H D proton transfer to the departing thiophenolate ion in the transition state.