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...

Bay-region diol epoxides are ultimate carcinogenic metabolites of a number of polycyclic aromatic compounds. Dibenz[a, h]acridine can form two diastereomeric pairs of these diol epoxides which are not positionally equivalent as a result of the nitrogen atom at position 7. We have assessed the structure-activity relationships resulting from heterocyclic nitrogen substitution by examining the mut...

The regioselective ring opening of styrene oxide using elemental iodine and bromine in the presence of disulfides as new catalysts was studied. The conductivity titration and UV spectroscopy were used to study the interaction of iodine with these catalysts. The results indicate that disulfide 11 is efficient in polyiodide formation, and can catalyze this reaction in excellent yield and high reg...

Bay-region diol epoxides are ultimate carcinogenic metabolites of a number of polycyclic aromatic compounds. Dibenz|a,/t|acridine can form two diastereomeric pairs of these diol epoxides which are not positional!) equivalent as a result of the nitrogen atom at position 7. We have assessed the structure-activity relationships resulting from heterocyclic nitrogen substitution by examining the mut...

The design of reactive species that can either serve to initiate the ring-opening polymerization epoxides for synthesis high molar mass polyethers or be alternatively used catalyze polyether telechelics in presence chain transfer agents has long been an elusive goal. Here, we report a series bifunctional borinane-based catalysts enable living with unprecedented activity (TOF ? 1.8 × 105 h–1) an...

This article summarizes and reviews recent progress in the development of catalysts for the ring-opening copolymerization of carbon dioxide and epoxides. The copolymerization is an interesting method to add value to carbon dioxide, including from waste sources, and to reduce pollution associated with commodity polymer manufacture. The selection of the catalyst is of critical importance to contr...

bon. Recent studies have shown that little if any B(e)P3(Chart i ) is metabolized to B(e)P 9,i 0-dihydrodiol by cultured hamster embryo cells (i 5) and rat liver microsomes,4 and little if any B(e)P dihydrodiol is metabolized to its bay-region diol-epoxide diastereomers by rat liver microsomes (i 2, 28). While the reason for the negligible amount of B(e)P 9, 10-dihydrodiol formation has not bee...

We found that elemental iodine and bromine are converted to trihalide nucleophiles (triiodine and tribromide anion, respectively) in the presence of catalytic amounts of meso-tetraphenylporphyrins (H2TPP). Therefore a highly regioselective method for the synthesis of beta-haloalcohols through direct ring opening of epoxides with elemental iodine and bromine in the presence of H2TPPs as new cata...