- A larene/ fragrant mixedsurrounds uncle butanol method for preparing ester compounds
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The invention discloses a preparation method of an aromatic ring/aromatic heterocycle tert-butyl alcohol ester compound. The preparation method of the aromatic ring/aromatic heterocycle tert-butyl alcohol ester compound comprises the following steps of: firstly, under stirring condition, adding aromatic heterocycle borate compound or aromatic ring boric acid compound and di-tert-butyl dicarbonate ester into a solvent, and then adding a palladium catalyst and a ligand, so that a mixture A is obtained; secondly, heating the mixture A for carrying out reaction, and then cooling to room temperature, so that a mixture B is obtained; thirdly, diluting the mixture B with ethyl acetate, then filtering the diluted mixture B with diatomite, collecting filtrate, concentrating, and carrying out spin drying, so that the aromatic ring/aromatic heterocycle tert-butyl alcohol ester compound is obtained. The preparation method of the aromatic ring/aromatic heterocycle tert-butyl alcohol ester compound has the advantages that alkoxycarbonylation reaction on an aromatic heterocycle borate compound or aromatic ring boric acid compound is realized, and the aromatic ring/aromatic heterocycle tert-butyl alcohol ester compound is directly generated; raw materials are non-toxic, inexpensive and available; a catalytic system is low in cost and has good stability and broad applicability; reaction conditions are mild, safety is high, and control is easy; a technology is simple, operation is easy, environmental friendliness is realized, and specificity is strong, so that the preparation method of the aromatic ring/aromatic heterocycle tert-butyl alcohol ester compound is applicable to industrialized production.
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Paragraph 0034-0041
(2017/02/02)
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- Intramolecular rearrangement of α-azidoperoxides: An efficient synthesis of tert-butyl esters
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An unprecedented intramolecular rearrangement of α-azidoperoxides, promoted by simple organic base to provide tert-butyl esters, has been presented. Further, a one-pot methodology consisting of in situ generation of the α-azidoperoxides from corresponding aldehydes followed by base-promoted rearrangement to obtain the desired ester has also been executed. Relevant mechanistic studies, to provide the proof for intramolecular alkoxy transfer, are investigated.
- Pramanik, Suman,Reddy, Reddy Rajasekhar,Ghorai, Prasanta
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p. 1393 - 1396
(2015/03/30)
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- A mesoporous organosilica grafted Pd catalyst (MOG-Pd) for efficient base free and phosphine free synthesis of tertiary butyl esters via tertiary-butoxycarbonylation of boronic acid derivatives without using carbon monoxide
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A mesoporous organosilica grafted palladium(ii) catalyst was synthesized and characterized using various spectroscopic techniques. Its catalytic activity was evaluated for the synthesis of tertiary butyl esters via tert-butoxycarbonylation of boronic acid
- Ghosh, Kajari,Molla, Rostam Ali,Iqubal, Md. Asif,Islam
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supporting information
p. 3540 - 3551
(2015/06/25)
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- Preparation of tert-butyl esters via Pd-catalyzed tert-butoxycarbonylation of (hetero)aryl boronic acid derivatives
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A novel protocol to synthesize tert-butyl esters from boronic acids or boronic acid pinacol esters and di-t-butyl dicarbonate has been successfully achieved. The cross-coupling reactions can produce up to 94% yields by using palladium acetate and triphenylphosphine as catalyst system, dioxane as a solvent. Moreover, a wide range of substrates including benzenes, pyridines, and quinolines boronic acids or boronic acid pinacol esters can fit with this system as well.
- Wu, Yusheng,Li, Xinjian,Zou, Dapeng,Zhu, Helong,Wang, Yaping,Li, Jingya,Wu, Yangjie
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supporting information
p. 1836 - 1839
(2014/05/06)
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- An efficient method for the preparation of tertiary esters by palladium-catalyzed alkoxycarbonylation of aryl bromides
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The palladium-catalyzed alkoxycarbonylation of aryl bromides is described for the efficient preparation of tertiary esters. The protocol proved compatible with a wide variety of functionalized (hetero)aromatic bromides, as well as several different sterically hindered tertiary alcohols, affording the alkoxycarbonylated products in high yields. Finally, the formation of aromatic trityl esters is discussed.
- Xin, Zhuo,Gogsig, Thomas M.,Lindhardt, Anders T.,Skrydstrup, Troels
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supporting information; experimental part
p. 284 - 287
(2012/02/16)
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- Sonogashira coupling reactions in biodegradable ionic liquids derived from nicotinic acid
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The biodegradable ionic liquids, 3-butoxycarbonyl-1-methylpyridinium bis(trifluoromethanesulfonyl)imides (1a-d), have been evaluated as solvents for copper- and phosphine-free Sonogashira coupling reactions. The stability of these ionic liquids toward basic conditions was analysed in order to further probe their utility for transition metal catalyzed reactions which require the presence of a base.
- Harjani, Jitendra R.,Abraham, Theodore J.,Gomez, Alwyn T.,Garcia, M. Teresa,Singer, Robert D.,Scammells, Peter J.
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experimental part
p. 650 - 655
(2010/08/22)
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- Transition-metal catalyzed oxidations. 7. Zirconium-catalyzed oxidation of primary and secondary alcohols with hydroperoxides
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A new procedure for the oxidation (dehydrogenation) of primary and secondary alcohols employing Zr(O-t-Bu)4 or Zr(O-n-Pr)4/tert-butyl hydroperoxide/3 A molecular sieves is presented. Secondary alcohols - if not severely sterically hindered - are usually converted quantitatively to the corresponding ketones. Esters or acids can be by products in the reaction of primary alcohols. However, the aldehydes are obtained in good yield by lowering the reaction temperature, decreasing the amount of TBHP or replacing TBHP by cumene hydroperoxide (CHP), and/or exchanging the catalyst Zr(O-t-Bu)4 by Zr(O-n-Pr)4 or silica gel-supported Zr(OR)(x). A remarkable selectivity of equatorial alcohol groups (e.g., 11 and 13) is observed in contrast to chromium(VI)-based oxidations. Strongly chelating substrates such as furfuryl alcohol (18) or 1,2-diol 25 that prevent hydride transfer in the six-membered transition state A are not converted.
- Krohn, Karsten,Vinke, Ingeborg,Adam, Horst
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p. 1467 - 1472
(2007/10/03)
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- GAS-PHASE PYROLYTIC REACTIONS. PART 3. HAMMETT ρ CONSTANTS OF GAS-PHASE ELIMINATIONS OF ALKYLARYLCARBOXYLATE AND ETHANOATE ESTERS AND THEIR CORRELATION WITH SUBSTRATE MOLECULAR FRAMEWORK
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The kinetics of the gas-phase thermal elimination of seven tert-butyl (hetero)arylcarboxylate esters (GCO2But) were measured over a temperature range 50 K; the groups were the phenyl, 3- and 4-pyridyl, 2- and 3-furyl, and 2- and 3-thienyl moieties.The reactions were homogeneous and unimolecular with log A/s-1 scaling 12.45 +/- 0.44, and with an entropy of activation uniformly negative and small.The kinetics obeyed a first-order rate equation, and at 600 K the rate coefficients (103k/s-1) of the esters, in the order given above, were: 54.1, 85.3, 120.5, 76.9, 43.2, 86.3 and 46.1, respectively.Hammett correlation of the present kinetic data with the literature ρ0 - values of the given substituents gave a reaction ρ constant compatible with the ethanoate molecular frame rather than with the carboxylate structure.The physical constants of five new t-butyl heteroarylcarboxylate esters are also described.
- Al-Awadi, Nouria A.,Al-Bashir, Rasha F.,ElDusouqui, Osman M. E.
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p. 2903 - 2910
(2007/10/02)
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- 2,2'-CARBONYL-BIS(3,5-DIOXO-4-METHYL-1,2,4-OXADIAZOLIDINE) : II- REAGENT FOR THE DIRECT ESTERIFICATION OF CARBOXYLIC ACIDS.
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Reaction of carboxylic acids including N-protected α-amino acids with 2,2'-carbonyl bis(3,5-dioxo-4-methyl-1,2,4-oxadiazolidine) and alcohols affords the corresponding esters under mild conditions.
- Grenouillat, Denis,Senet, Jean-Pierre,Sennyey, Gerard
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p. 5827 - 5828
(2007/10/02)
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- A Simple, Powerful, and Efficient Method for Transesterification
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Aromatic and α,β-unsaturated methyl esters undergo efficient transesterification at ambient temperature or below with primary, secondary, or (particularly) tertiary alcohols in the presence of butyl-lithium in tetrahydrofuran solution.
- Meth-Cohn, Otto
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p. 695 - 697
(2007/10/02)
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