80582-67-8Relevant academic research and scientific papers
STEREOCHEMICAL ARGUMENTS AGAINST A POSSIBLE CHLOROHYDRIN ROUTE IN THE CATALYTIC EPOXIDATION OF OLEFINS WITH NaOCl/Mn-porphyrins.
Carvalho, Maria-Eliza De,Meunier, Bernard
, p. 3621 - 3624 (1983)
The stereochemistry of the epoxidation of norbornene and 3-carene with the NaOCl/Mn(TPP)OAc system is the same as that observed with peracids, suggesting that the chlorohydrin route does not occur in this catalytic epoxidation.
Highly selective olefin epoxidation with the bicarbonate activation of hydrogen peroxide in the presence of manganese(III) meso-tetraphenylporphyrin complex: Optimization of effective parameters using the Taguchi method
Monfared, Hassan Hosseini,Aghapoor, Vahideh,Ghorbanloo, Massomeh,Mayer, Peter
experimental part, p. 209 - 216 (2011/02/16)
A MnIII-porphyrin-based catalytic system was explored for olefin epoxidations under mild reaction conditions using sodium bicarbonate-hydrogen peroxide as an oxidant. The Mn(TPP)OAc/imidazol/NaHCO3 system efficiently catalyzed the epoxidation of olefins with H2O2. Cyclic olefins were transformed in excellent yield (80-100%) and selectivity (87-100%), the obtained selectivity and yields being much better than those observed in the absence of bicarbonate. In the presence of an excess of substrate, the turnover number 4286 was obtained with the Mn(TPP)OAc/Im/NaHCO3/H2O2 system after 2 h. The bicarbonate-activated oxidation system is a simple, inexpensive, and relatively nontoxic alternative to other oxidants and peroxyacids, and it can be used in a variety of oxidations where a mild, neutral pH oxidant is required. Due to the various factors, such as solvent, reaction temperature, stoichiometric ratio of imidazole/NaHCO3/H2O2, influencing the oxidation of olefins, the Taguchi method of system optimization was used to determine the percent of contribution (%P) of each factor. It was found that the solvent had the most influence on the oxidation (30.051%) and the imidazole amount stood in second place (22.286%).
Novel (α,β-Epoxyalkyl)lithium Reagents via the Lithiation of Organyl-Substituted Epoxides
Eisch, John J.,Galle, James E.
, p. 4835 - 4840 (2007/10/02)
A series of epoxides bearing unsaturated organyl groups attached directly to the epoxy group was found to have sufficient kinetic acidity to undergo clean lithiation at low temperatures.Epoxides of the type is aryl, vinylic, acetylenic, alkoxycarbonyl, or cyano, were smoothly converted into by either t-BuLi or LDA in the temperature range of -80 to -115 deg C.The resulting (α,β-epoxyalkyl)lithium reagents could be transformed into a variety of substituted epoxides, such as R2C-CE(Un)-O, where E = D, R3Si, R3Sn, R, RCO, CO2H, or COH(R)2.In cases where Un is acyl, addition to the carbonyl, rather than lithiation, occurred preferentially.Attempted lithiations of aziridines and thiiranes led to extrusion of nitrogen and sulfur, respectively.Even the relatively stable intermediates generated at -90 deg C underwent carbenoid-like decomposition at higher temperatures to yield isomerization and intermolecular-insertion products.Observation of these processes gives direct corroboration of reaction mechanisms proposed for the base-promoted isomerizations of epoxides.
Introduction of a Triple Bond into the Bicyclononane skeleton
Meier, Herbert,Antony-Mayer, Christina,Schulz-Popitz, Cornelius,Zerban, Georg
, p. 1087 - 1094 (2007/10/02)
The introduction of a triple bond into the bicyclononane skeleton is investigated by applying the selenadiazole method to ketones 1a-c, accessible on different pathways.The highly strained bicyclononynes 2a and 2b can be isolated in pure state.The regioselectivity of the ring-closure reaction yielding the selenadiazoles determines the position of the triple bond.
