82777-35-3Relevant academic research and scientific papers
Hydrosulfonylation of Unactivated Alkenes by Visible Light Photoredox Catalysis
Wang, Juan-Juan,Yu, Wei
supporting information, p. 9236 - 9240 (2019/11/19)
The anti-Markovnikov hydrosulfonylation of unactivated alkenes with sodium sulfinates was realized via [Ir(dF(CF3)ppy)2(dtbbpy)]PF6-mediated visible light photoredox catalysis. The presence of an acid such as acetic acid is essential for the reaction to take place. A variety of unactivated alkenes can be transformed into sulfones with good yield and high regioselectivity using this reaction, which is proposed to proceed by a radical mechanism.
Intramolecular Reactions. Part 12. Ring Size and Leaving Group Effects on Inter- and Intra-molecular Nucleophilic Substitution by Carbanions
Bird, Roger,Griffiths, Gwerydd,Griffiths, Gwynfor F.,Stirling, Charles J. M.
, p. 579 - 584 (2007/10/02)
In cyclisations of aryl ο-halogenoalkyl ketones to aryl cycloalkyl ketones with base, cyclopropanes are formed up to 23000 times faster than cyclopentanes.Hydrogen-deuterium exchange experiments and very low bromide-chloride ratios (1.9) for three-membered ring formation are consistent with rate-determining deprotonation of the ketone.By contrast, in five-membered ring formation, hydrogen-deuterium exchange adjacent to the carbonyl group occurs much faster than cyclisation and the chloride-bromide ratio is 'normal' at 99.In formation of arylsulphonylcyclopropanes from arylsulphonylpropyl arenesulphonates, the Hammett ρ value for the leaving group is +1.7, and for intermolecular substitution by bis-sulphonyl stabilised carbanions, +1.2.Attempts to obtain ρLG values for five-membered ring formation were frustrated by competing intermolecular reactions.The results are discussed against the background of previous work on ring formation by intramolecular nucleophilic substitution.
