- Ring opening epoxides into halohydrins with elemental iodine and bromine in the presence of nano catalyst ZrO2
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There is a continued interest in the regioselective ring opening of oxiranes to the corresponding vicinal halohydrins. Although a variety of new and mild procedures to effect this transformation have been reported, most of them have some limitations.The ring opening of epoxides with elemental bromine and nano catalyst ZrO2 affords vicinal bromo alcohols in high yields. This new procedure occurs regioselectively under neutral and mild conditions in various aprotic solvents even when sensitive functional groups are present.
- Azizian, Javad,Shameli, Abolghasem,Balali, Ebrahim,Ghanbari, Mohammad Mehdei,Zomorodbakhsh, Shahab
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p. 1361 - 1364
(2013/02/23)
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- Highly facile biomimetic regioselective ring opening of epoxides to halohydrins in the presence of β-cyclodextrin
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Highly regioselective ring opening of epoxides to halohydrins has been carried out in impressive yields with hydrogen and lithium halides in presence of β-cyclodextrin using water as solvent.
- Reddy, M.Arjun,Surendra,Bhanumathi,Rao, K.Rama
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p. 6003 - 6008
(2007/10/03)
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- 3, 5, and/or 6 substituted analogues of swainsonine processes for their preparation and their use as therapeutic agents
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The invention relates to novel 3, 5, and/or 6 swainsonine analogues, processes for their preparation and their use as therapeutic agents. The invention also relates to pharmaceutical compositions containing the compounds and their use as therapeutics.
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- Regiocontrolled Opening of Cyclic Ethers Using Dimethylboron Bromide
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The cleavage of various cyclic ethers (3- to 7-membered rings) was achieved under very mild conditions using dimethylboron bromide to afford the corresponding bromo alcohols.In particular, 2-substituted tetrahydrofurans were regioselectively cleaved by a predominantly SN2 - type mechanism favoring the formation of primary vs. secondary bromides.Dimethylboron bromide also cleaved chemoselectively substituted tetrahydrofurans in the presence of functional groups such as acyclic ethers, silyl ethers, esters, amides, ketones,etc.
- Guindon, Yvan,Therien, Michel,Girard, Yves,Yoakim, Christiane
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p. 1680 - 1686
(2007/10/02)
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- CONVERSION OF EPOXIDES TO BROMOHYDRINS BY B-BROMOBIS(DIMETHYLAMINO)BORANE
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Reaction of the title reagent with 1-alkene oxides regioselectively yields the corresponding 1-bromo-2-alkanols, while the more substituted bromide predominates in the cases of styrene oxide and 1-methylcyclohexene oxide.
- Bell, Thomas W.,Ciaccio, James A.
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p. 827 - 830
(2007/10/02)
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