- Bronsted acid catalyzed asymmetric SN2-Type O-alkylations
-
Bridging the gap: Bronsted acids catalyze an intramolecular S N2-type alkylation of alcohols with ethers by bridging a pentacoordinate transition state, thus simultaneously activating both the leaving group and nucleophile (see scheme). Density functional calculations provide detailed insight into the course of the reaction and the transition-state structure.
- Coric, Ilija,Kim, Ji Hye,Vlaar, Tjostil,Patil, Mahendra,Thiel, Walter,List, Benjamin
-
supporting information
p. 3490 - 3493
(2013/05/09)
-
- Amberlyst-15-catalyzed one-pot synthesis of 2-aryltetrahydrofurans from tetrahydrofuran
-
A simple one-step route for the conversion of naphthols and phenols with tetrahydrofuran into corresponding 2-aryltetrahydrofurans using Amberlyst-15 as a catalyst is reported. This is the first example of the acid-mediated formation and rearrangement reactions of tetrahydrofuranyl ethers prepared from the tetrahydrofuran and aromatic/aliphatic hydroxy compounds.
- Gunduz, Hande,Kumbaraci, Volkan,Talinli, Naciye
-
supporting information
p. 2473 - 2476,4
(2012/12/13)
-
- The selective functionalization of saturated hydrocarbons. Part 40. Aspects of Fe(II) based peroxide fragmentation in pyridine solution
-
The Haber-Weiss mechanism does not apply to the Fe(II) induced fragmentation of primary and secondary hydroperoxides in pyridine. However, it does apply to tertiary hydroperoxides. Steric bulk is an important factor in Fe(II) induced dialkyl peroxide decomposition in pyridine. On the contrary in tetrahydrofuran a different relatively unhindered electron transfer process predominates where the Fe(II) becomes a catalyst.
- Barton, Derek H. R.,Launay, Franck
-
p. 14565 - 14578
(2007/10/03)
-
- Decomposition Induite de Peroxydes Acetyleniques
-
Acetylenic peroxides react as radicals in good hydrogen-donor solvents.Addition to the triple bond leads to monoadducts and attack on the O-O bond gives unsaturated acetals.The intermediate vinyl radical obtained in the first case does not seem to lead to homolytic intramolecular substitution.Unlike their ethylenic homologous these compounds are not unsaturated heterocycle precursors.
- Lemee, Laurent,Bourgeois, Marie-Josephe,Montaudon, Evelyne
-
p. 467 - 472
(2007/10/03)
-
- Catalytic oxidation of homoallylalcohols to α-alkoxytetrahydrofurans by a Pd-nitro complex and molecular oxygen
-
Various homoallylalcohols were highly regioselective oxidized with molecular oxygen at the terminal carbon to afford cyclic acetals (α-alkoxytetrahydrofurans) using PdNO2CL(CH3CN)2 as catalyst in the presence of CuCL2 and t-butanol or isopropanol.
- Meulemans, Tom M.,Kiers, Niklaas H.,Feringa, Ben L.,Van Leeuwen, Piet W. N. M.
-
p. 455 - 458
(2007/10/02)
-
- Direct Facile Tetrahydrofuranylation Of Alcohols Through Radical Coupling With (Bu4N)2S2O8
-
Primary, secondary and tertiary alcohols can be converted in excellent yields into their 2-tetrahydrofuranyl-ethers in the presence of n-tetrabutylammonium peroxydisulfate under nearly neutral condition in tetrahydrofuran.
- Jung, Jae Chul,Choi, Hyun Chul,Kim, Yong Hae
-
p. 3581 - 3584
(2007/10/02)
-
- Cerium(IV)-Mediated Synthesis of Tetrahydrofuranyl Ethers
-
The reaction of tetrahydrofuran with an alcohol in the presence of ceric triethylammonium nitrate provides a convenient and general procedure for protecting the hydroxyl function.Tetrahydrofuranyl ethers of primary, secondary and tertiary alcohols were obtained in good yields.
- Maione, Anna M.,Romeo, A.
-
p. 250 - 251
(2007/10/02)
-
- DEPLACEMENTS HOMOLYTIQUES INTRAMOLECULAIRES . 12 - DECOMPOSITION INDUITE DE PEROXYDES ETHYLENIQUES : INFLUENCE DE LA LONGUEUR DE LA CHAINE
-
Products analyses of the thermolyses of the peroxides CH2=CH-(CH2)nOOtBu, 1, (n=1-5) showed that an induced decomposition of 1 occurred for n=1,2,3,4.Free radical additions of THF, carbon tetrachloride, bromotrichloromethane to 1 have been performed at lower temperature; they allowed, through the isolation of an adduct peroxide, at least in one case for each peroxide, to prove that a two-steps mechanism (addition of radical Z. to the double bond, intramolecular homolytic displacement) is involved in the induced decomposition of 1.The order of magnitude of the rate constants of these SHi reactions could be estimated.
- Bourgeois, M. J.,Maillard, B.,Montaudon, E.
-
p. 5309 - 5320
(2007/10/02)
-
- Deplacements homolytiques intramoleculaires. 2. Decomposition du perpentene-4 oate de tert-butyle dans les ethers
-
The thermolysis of tert-butyl perpent-4-enoate 1 in THF led to several compounds; the main product, 5-(2-tetrahydrofuryl)-4-pentanolide (yield 42percent) comes from an induced decomposition of the perester occuring with the addition of 2-tetrahydrofuryl radical to the double bond.A similar reaction was performed at a lower temperature, using butyl perdicarbonate as initiator, but did not define the mechanism (concerted or two-step).The thermolysis of 1 in ethers (THP, oxepane, 1,4-dioxane, dipropyl ether) appears to be a useful synthetic tool: several new γ-lactones have been obtained in this way.
- Kharrat, A.,Gardrat, C.,Maillard, B.
-
p. 2385 - 2390
(2007/10/02)
-
- Obtention d'aldehydes γ-fonctionnels au cours de la thermolyse du percarbonate de O,O-t-butyle et O-vinyle en solution
-
Owing to its peroxyester group, O,O-tert-butyl and O-vinyle peroxycarbonate may act as a free radical initiator in solution, but also, due to the presence of the vinylic insaturation, as a substrate for free radical addition reactions. - In such solvents as cumene which give free radicals unable to add to the double bond, the peroxycarbonate merely behaves as a vinyloxy radicals generator.It is thus possible to observe these radicals reacting either as formylmethyl radicals or as acetyl radicals. - In solvents such as cyclohexane which give free radicals able to add to the double bond, the reaction results in the substitution of formylmethyl groups to labile hydrogens of the solvent. - By applying the reaction to such compounds as ketones, ethers, acids and their derivatives, we could obtain γ-functional aldehydes (γ-ketoaldehydes, γ-oxaaldehydes and derivatives of succinaldehydic acids).These products are often difficult to prepare by other routes and until now only some of them have been described.
- Filliatre, Claude,Villenave, Jean-Jacques,Jaouhari, Rabih,Baratchart, Michel
-
p. 352 - 356
(2007/10/02)
-