poly (n-bromosuccinimide) (pnbs) as a mild, efficient, non-acidic, polymeric and heterogeneous catalyst was applied for simple conversion of epoxides into thiiranes by treatment with kscn or (nh2)2cs at room temperature. aliphatic and aromatic epoxides converted into their corresponding thiiranes under mild conditions. all reactions proceeded in short reaction times and afforded the correspondi...

We have investigated the photofragmentation properties of the three-membered ring heterocyclic molecule ethylene sulfide or thiirane, C(2)H(4)S, by time-of-flight mass spectroscopy. Positive ions have been collected as a function of photon energy around the S K ionization threshold. Branching ratios were derived for all detected ions, which are informative of the decay dynamics and photofragmen...

Taking into account the thiophilic properties of iodine, a very simple methodology to achieve 2 0,3 0-didehydro-2 0,3 0-dideoxy-b-nucleosides in high yield was performed, using mild, and inexpensive conditions, by means of the treatment of 2 0-deoxy-3 0,5 0dibenzoyl-2 0-iodo-b-nucleoside derivatives with NaHS. The process has shown to be highly dependent of the relative geometry between the iod...

An intriguing stepwise diradical mechanism of the dimerization of the reactive intermediate (thiocarbonyl S-methanide) appearing in the reaction of phenyl selenophen-2-yl thioketone with diazomethane was studied by means of computational methods. The preferred formation of the unusual macroheterocycle, competitive with the 1,3-ring closure leading to a thiirane and the head-to-head dimerization...