A recyclable biphasic system for stereoselective and easily handled hydrochalcogenations
Vinyl selenides and vinyl sulfides were prepared by hydrochalcogenation of alkynes with selenols and thiols generated in situ by the reduction of the corresponding diselenides and disulfides with elemental zinc in a biphasic acidic medium. The yields, ste
Preparation, structure, and chemistry of phosphorane-derived phenyliodonium sulfonates
New triphenylphosphorane-derived phenyliodonium triflates and tosylates were prepared by the reaction of the appropriate iodosobenzene sulfonate with stabilized phosphonium ylides. Structure of the triflate derivative was determined by a single-crystal X-
Zhdankin, Viktor V.,Maydanovych, Olena,Herschbach, Jon,Bruno, Jessica,Matveeva, Elena D.,Zefirov, Nikolai S.
p. 2359 - 2361
(2007/10/03)
Reaction of Benzenesulphenyl Chloride with α, β-Unsaturated Compounds: Part I - Reactions with Methyl Crotonate and Methyl Cinnamate in Presence of Pyridine
Reaction of benzenesulphenyl chloride (PhSCl) with α, β-unsaturated systems, in the presence of pyridine, offers a convenient route to sulphenylate regiospecifically the α-position of such systems.The specific role of pyridine and the product analysis have been examined and rationalised on the basis of the formation of pyridine-assisted carbanion intermediates and the structure/stability of these carbanions.
Bhongle, N. N.,Gogte, V. N.,Vankar, Y. D.
p. 724 - 728
(2007/10/02)
THE AdNSNE MECHANISM IN THE REACTION OF PHENOL AND BENZENETHIOL WITH α-BROMO MICHAEL ACCEPTORS IN THE K2CO3-ACETONE SYSTEM
In the reaction of α-bromo Michael acceptors with either phenol or benzenethiol formal substitution of the vinylic bromine proceeds through addition of the phenolic reagent, followed by nucleophilic substitution and β-elimination (AdNSNE mechanism) in the system K2CO3-acetone.The process is shown to be stereospecific in the case of 2a,b and 3b,c, leading to the corresponding Z isomer.The reactivity of substrates 1-4 is discussed in terms of their structural features.