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Showing 1 to 13 of 13 for “"Cyclic ethers"”.
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The cationic ring-opening polymerization of cyclic ethers
… polymerization and copolymerizntion of different cyclic ethers were studied using mainly a cationic system of iinitiation. BF30Et2/ethanediol. The cyclic ethers reacted differently showing that ring strain and basicity are the main driving forces in cationic ring opening polymerizaion. In most …
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The ring opening polymerization of ring strained cyclic ethers
The kinetics and mechanisms of the ring-opening polymerization of oxetane were studied using cationic and coordinated anionic catalysts. The cationic initiators used were BF30Et2!/ethanol, BF30Et2!/ethanediol and BF30Et2/propantriol. Kinetic determinations with the BF30Et2/diol system indicated …
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Computational Studies of Protonated Cyclic Ethers and Benzylic Organolithium Compounds
… more symmetrical charge distribution and cyclic homologues featuring less ring strain are treated with greater accuracy by B3LYP. Ion-pair separation (IPS) of THF-solvated fluorenyl, diphenylmethyl, and trityl lithium was studied computationally. Minimum-energy equilibrium geometries of …
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Generation of Alkyl Radicals Via C-H Functionalization and Halogen Atom Transfer Processes
… C(sp3)-H functionalization of aliphatic cyclic ethers using trace O2. This reaction uses a trace amount of aerobic oxygen as the sole green oxidant under blue light at room temperature to achieve the synthesis of sulfone and phosphate derivatives in good to excellent yields using cyclic …
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Ether Chemistry On Si(100) And Desorption Kinetics Of Corresponding Alkyls And Alkoxides
… complex adsorbate systems, such as linearand cyclic ethers, which produced a mixture of surface products.
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EXPLORATIONS IN MEDIUM-RING ETHER SYNTHESIS VIA UMPOLUNG HETEROATOM ACTIVATION: TOTAL SYNTHESIS, METHODS DEVELOPMENT, AND REAGENT SYNTHESIS
… challenges include 7- and 8-membered medium-ring ethers and isolated stereogenic centers. A novel (bis)cationic nitrogen-ligated HVI (NHVI)-mediated oxidative rearrangement represents and innovative approach to the Heliannuols by providing expedient access to the challenging cyclic ether scaffold …
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Thermochemistry and bond energies of acetohydrazide, amides and cyclic alkyl ethers
… approach is acceptable for larger molecules. Cyclic ethers are a major initial product from the reactions or hydrocarbon radicals with triplet dioxygen (^3O_2) in low to moderate temperature oxidation and combustion reaction systems and atmospheric chemistry of small hydrocarbons. …
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Thermochemistry of fluorinated aldehydes and corresponding radicals;thermochemistry and kinetics of diethyl ether and ethyl oxirane relative to reactions under atmospheric and combustion conditions
… comparison to available literature values. Ethers C—H BDEs in the primary position in comparison to the secondary position increase by 3-8 kcal mole^{-1} for aliphatic chains. Cyclic ethers posses Entropies (S*298 in cal/mole K) are estimated using B3-LYP methodology with basis sets …
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Studies of the cationic polymerisation of vinylic and energetic cyclic ether monomers
… polymerisation of various monomers, including cyclic ethers bearing energetic nitrate ester (-ON02) groups, substituted styrenes and isobutylene has been investigated. The main reaction studied has been the ring-opening polymerisation of 3- (nitratomethyl)-3-methyl oxetane (NIMMO) using the …
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Thermochemistry reaction paths and oxidation kinetics on ketonyl and aldehydic nitrogen oxides, propene and isooctane: a theoretical study
… isooctene plus HO_2. Next important products are cyclic ethers plus OH radical. This research is the first fundamentally based study of relevant pathways on the potential energy surfaces of tert-isooctane radicals + O_2 using high level composite calculation methods. Kinetic modeling for OH …
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Synthetic studies of sodium aminodiboranate salts with electronwithdrawing substituents
… BH3. To circumvent this problem, we employed non-cyclic ethers such as diglyme and cyclopentyl(methyl)ether to investigate the preparation of μ-aminodiborane(6) species from the fluorinated amines N,N-bis(2,2,2-trifluoroethyl)¬amine, N-(2,2,2-trifluoroethyl)amine, and …
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Iridium-catalyzed borylation of aromatic and aliphatic C-H bonds: methodology and mechanism
… C-H bonds, specifically secondary C-H bonds of cyclic ethers, with a catalyst generated from tetramethylphenanthroline and an iridium precursor is reported in Chapter 4. This borylation occurs with unique selectivity for the C-H bonds located β to the oxygen atoms over the weaker C-H bonds …