- 19F-NMR ANALYSES OF SOME CYCLOPROPANE DERIVATIVES
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Structural assignments of all possible diastereomers of 1-chloro-2-ethoxy-1-fluoro-alkylcyclopropanes have been achieved through their 19F-NMR spectra.The previously unreported effect of an ethoxyl group on the fluorine signal has been studied and found to promote in most cases a shielding effect in the vicinal cis-fluorine and a deshielding effect when trans to this halogen.
- Camps, F.,Coll, J.,Fabrias, G.,Guerrero, A.,Feliz, M.
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- An effective combination catalyst of CeO2and zeolite for the direct synthesis of diethyl carbonate from CO2and ethanol with 2,2-diethoxypropane as a dehydrating agent
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The combination catalyst of CeO2 and H-FAU zeolite was effective for the direct synthesis of diethyl carbonate from CO2 and ethanol with 2,2-diethoxypropane as a dehydrating regent, where H-FAU catalyzed hydrolysis of 2,2-diethoxypropane. The combination catalyst provided high activity and a high diethyl carbonate yield of 72% based on 2,2-diethoxypropane at a low temperature of 393 K. This journal is
- Chang, Tao,Choi, Jun-Chul,Fukaya, Norihisa,Hamura, Satoshi,Matsumoto, Seiji,Mishima, Takayoshi,Nakagawa, Yoshinao,Tamura, Masazumi,Tomishige, Keiichi
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p. 7321 - 7327
(2020/11/23)
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- Synthesis of Fischer carbene complex of iridium by C-H bond activation of methyl and cyclic ethers: Evidence for reversible α-hydrogen migration
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We report here a mild and versatile route to Fischer carbene complexes of iridium via the activation of C-H bonds of methyl and cyclic ethers, along with our preliminary studies of this rare family of carbene complexes. Theoretical studies suggest that α-hydrogen migrations can be kinetically favorable if a coordinatively unsaturated species can be accessed. Thus, the lability of the triflate ligand presumably facilitates this process. Further evidence for the rapidity, as well as reversibility, of this rearrangement was obtained by NMR analysis.
- Luecke,Arndtsen,Burger,Bergman
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p. 2517 - 2518
(2008/10/08)
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- Phenylation of cationic allylpalladium(II) complexes by tetraphenylborate anion. A mechanistic study
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The mechanism of the reaction of allyl complexes 3-2-R'C3H4)(N-N')>+ (N-N' = α-diimine ligand) with BPh4- in the presence of activated olefins (ol), yielding the products 2-ol)(N-N')> and PhCH2C(R')=CH2, has been investigated.The results are interpreted in terms of extensive association between the cationic substrate and the BPh4- anion in a tight ion-pair, followed by rate-determining phenyl transfer to the palladium center and fast reductive elimination of allylbenzene.
- Crociani, Bruno,Bianca, Francesca Di,Canovese, Luciano,Uguagliati, Paolo
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p. C17 - C20
(2007/10/02)
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- Dissociation of Positively Charged Aliphatic Epoxides. II. +. Epoxides and α,β Unsaturated Ethers
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The unimolecular dissociations of C5 epoxides ions mono- or disubstituted at C1 give exclusive loss of CH3 and exclusive formation of methoxyvinyl carbenium ion, both in the source and in the 2nd field-free region.In the case of the 1,2-disubstituted ion in the 2nd field-free region the loss of ethene is the only pathway, while a competition occurs for the trisubstituted ion leading to +. and +. ions, the structure of which are demonstrated.The first step of the different mechanisms is the cleavage of the heterocyclic C-C bond.
- Bouchoux, Guy,Djazi, Feycal,Hoppilliard, Yannik,Jaudon, Pascale,Nouts, Nathalie
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- A CONVENIENT AND STEREOSELECTIVE SYNTHESIS OF (3Z,5Z)-5-FLUOROTETRADECADIEN-1-YL ACETATE, A FLUORINATED ANALOG OF THE SEX PHEROMONE OF THE CARPENTERWORM Prionoxistus robiniae (PECK)
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A convenient synthesis of (3Z,5Z)-5-fluorotetradecadien-1-yl acetate 1, a fluorinated analog of the sex pheromone of the carpenterworm Prionoxistus robiniae (Peck), through reaction of (Z)-2-fluoro-2-undecenal 4 with the previously unreported Wittig reagent 5,5-dimethyl-4,6-dioxaoctyltriphenylphosphonium chloride 6, is presented.
- Alcazar, A.,Camps, F.,Coll, J.,Fabrias, G.,Guerrero, A.
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p. 819 - 828
(2007/10/02)
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