- Palladium-Catalyzed Cyclobutanation of Aryl Sulfonates through both C-O and C-H Cleavage
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A palladium-catalyzed cyclobutanation of aryl sulfonates with strained alkenes has been developed. The methodology is featured to achieve the cleavage of both C-O and C-H bonds of phenol derivatives in one pot. Under the reaction conditions, in addition t
- Zhang, Liangwei,Liu, Long,Huang, Tianzeng,Dong, Qizhi,Chen, Tieqiao,Chen, Tieqiao
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p. 2189 - 2196
(2020/06/05)
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- Chromatography-Free and Eco-Friendly Synthesis of Aryl Tosylates and Mesylates
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Two chromatography-free and eco-friendly protocols have been developed to synthesize aryl tosylates and mesylates by the tosylation and mesylation of the corresponding hydroxyarenes, respectively. These protocols are superior to other known ones regarding
- Lei, Xiangyang,Jalla, Anusha,Abou Shama, Mhd A.,Stafford, Jamie M.,Cao, Billy
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supporting information
p. 2578 - 2585
(2015/09/01)
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- Palladium-catalyzed intra-and intermolecular C-H arylation using mesylates: Synthetic scope and mechanistic studies
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This paper describes the development of Pd-catalyzed inter-and intramolecular direct arylation using mesylates. Furthermore, a sequential mesylation/arylation protocol using phenols as substrates is described. These transformations are general with respect to the electronics of the C-H substrates and allow for the synthesis of diverse heterocyclic motifs in good yields. Both arenes and heteroarenes efficiently participate in these reactions. Preliminary mechanistic studies are presented for both inter-and intramolecular arylations.
- Ferguson, Devin M.,Rudolph, Stacey R.,Kalyani, Dipannita
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p. 2395 - 2401
(2014/07/21)
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- Cyanation of unactivated aryl chlorides and aryl mesylates catalyzed by palladium and hemilabile MOP-type ligands
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Palladium-catalyzed cyanation of aryl halides and pseudo halides with potassium hexacyanoferrate is described employing the hemilabile, bulky, and electron-rich MOP-type ligands. When the mixture of t-BuOH and H2O was used as the solvent and K2CO3 as the base, the MOP-type ligands showed high efficiency for the palladium-catalyzed cyanation. The effect of ligand structure was studied in detail, and 2-di-tert-butylphosphino-2′-isopropoxy-1,1′-binaphthyl was the more effective for the cyanation. The catalyst system allows the cyanation of unactivated aryl chlorides, and even aryl mesylates to occur in good yields. Furthermore, the reactivity of different arylated reagents in the catalytic system was found to be: ArBr > ArCl >> ArOMs > ArOSO2Im > ArOSO2NMe2.
- Tu, Yahui,Zhang, Yi,Xu, Sheng,Zhang, Zhaoguo,Xie, Xiaomin
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supporting information
p. 2938 - 2942
(2015/01/16)
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- Mechanistic insight into the formal [1,3]-migration in the thermal claisen rearrangement
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The thermal formal [1,3]-sigmatropic shift of allyl aryl ethers has been studied in depth experimentally with the aid of the density functional theory (DFT) calculations of the B3LYP function. Three mechanistic possibilities, referred to as the radical, ionic, and concerted mechanisms, have previously been put forth to explain the thermal [1,3]-rearrangement process. However, the intercrossing and radical trapping experiments indicate the rearrangement is an intramolecular process. The computational studies reveal that the concerted C[1,3]-sigmatropic shift suffered from a higher energetic barrier to allow the rearrangement to proceed under the conditions used. However, a tandem O[1,3]-sigmatropic shift with a configuration inversion of the oxygen atom and [3,3]-sigmatropic shift (the Claisen rearrangement) is the most likely pathway for the formal [1,3] rearrangement. Furthermore, the rearrangement experiments with a designed optically active substrate and O[1,3]-sigmatropic shift examples verify the new cascade rearrangement. In addition, computational and experimental studies indicate that water molecule assists the proton shift during the isomerization. The combined methods provide the new insight into the mechanism of the thermal formal [1,3]-migration in the Claisen rearrangement and the novel O[1,3]-sigmatropic shift as well.
- Hou, Shili,Li, Xinyao,Xu, Jiaxi
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p. 10856 - 10869
(2013/02/23)
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- Scope of direct arylation of fluorinated aromatics with aryl sulfonates
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The scope and limitations of direct arylation of fluorinated aromatics with aryl sulfonates was examined. Pd(OAc)2, in the presence of MePhos and KOAc in THF, efficiently catalyzed the direct arylation of fluoro aromatics with aryl triflates un
- Chang, Joyce Wei Wei,Chia, Eugene Yurong,Chai, Christina Li Lin,Seayad, Jayasree
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supporting information; experimental part
p. 2289 - 2299
(2012/04/10)
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- Nickel catalyzed cross-coupling of aryl C-O based electrophiles with aryl neopentylglycolboronates
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The efficiency of mesylates, sulfamates, esters, carbonates, carbamates, and methyl ethers as C-O-based electrophiles attached to the 1- or 2-position of naphthalene and to activated and nonactivated phenyl substrates was compared for the first time in Ni-catalyzed cross-coupling with phenyl neopentylglycolboronates containing electron-rich and electron-deficient substituents in their para-position. These experiments were performed in the presence of four different Ni(II)- and Ni(0)-based catalysts. Ni(II)-based catalysts mediate the cross-coupling of most 2-naphthyl C-O electrophiles with both arylboronic acids and with neopentylglycolboronates when K 3PO4 is used as base. The same catalysts are not efficient when CsF is used as base. However, Ni(0)-based catalysts exhibit selective efficiency, and when reactive, their efficiency is higher than that of Ni(II)-based catalysts in the presence of both K3PO4 and CsF. These results provide both reaction conditions for the cross-coupling, and for the elaboration of orthogonal cross-coupling methodologies of various C-O based electrophiles with aryl neopentylglycolboronates. With the exception of mesylates and sulfamates the efficiency of all other 2-naphthyl C-O electrophiles was lower in cross-coupling with aryl neopentylglycolboronates than with arylboronic acids
- Leowanawat, Pawaret,Zhang, Na,Percec, Virgil
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experimental part
p. 1018 - 1025
(2012/03/22)
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- Nickel-catalyzed C-P coupling of aryl mesylates and tosylates with H(O)PR1R2
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A method was developed for the nickel-catalyzed phosphonylation of aryl mesylates and tosylates with H(O)PR1R2. To the best of our knowledge, this is the first example of nickel-catalyzed C-P coupling of aryl mesylates and tosylates. Most of the substrates gave moderate to good yields under our catalytic system.
- Shen, Chaoren,Yang, Guoqiang,Zhang, Wanbin
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supporting information; body text
p. 3500 - 3505
(2012/05/20)
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- Palladium-catalyzed borylation of aryl mesylates and tosylates and their applications in one-pot sequential suzuki-miyaura biaryl synthesis
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Top of the one-pots! The first palladium-catalyzed borylation of aryl tosylates and mesylates is described. The reaction conditions are mild and provide excellent functional-group compatibility (e.g., R=CN, CHO, COOMe, C(O)R, NH2, or NH-indole; see scheme). Pd/MeO-CM-phos allows one-pot sequential reactions in the preparation of unsymmetrical biaryls. Copyright
- Chow, Wing Kin,So, Chau Ming,Lau, Chak Po,Kwong, Fuk Yee
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supporting information; experimental part
p. 6913 - 6917
(2011/08/03)
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- Neopentylglycolborylation of aryl mesylates and tosylates catalyzed by Ni-based mixed-ligand systems activated with Zn
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(Chemical Presented) The mixed-ligand system NiCl2(dppp)/dppf is shown to be an effective catalyst for the neopentylglycolborylation of ortho-, meta-, and para-substituted electron-rich and electrondeficient aryl mesylates and tosylates. The ad
- Wilson, Daniela A.,Wilson, Christopher J.,Moldoveanu, Costel,Resmerita, Ana-Maria,Corcoran, Patrick,Hoang, Lisa M.,Rosen, Brad M.,Percec, Virgil
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supporting information; experimental part
p. 1800 - 1801
(2010/04/24)
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- A general palladium catalyst system for suzuki-miyaura coupling of potassium aryltrifluoroborates and aryl mesylates
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(Figure presented) The first general examples of palladium-catalyzed Suzuki-type cross-coupling of aryl and heteroaryl mesylates with potassium aryl and heteroaryltrifluoroborates are presented. In addition to biaryl couplings, the cross-coupling reactions of aryl mesylates with alkyl and vinyltrifluoroborate salts have also been successfully accomplished.
- Chow, Wing Kin,So, Chau Ming,Lau, Chak Po,Kwong, Fuk Yee
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supporting information; experimental part
p. 5109 - 5112
(2010/09/05)
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- A mild and efficient palladium-catalyzed cyanation of aryl mesylates in water or tBuOH/water
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Cool and compatible: Aryl mesylates and tosylates underwent palladium-catalyzed cyanation under mild, aqueous conditions at 65-80°C (see scheme). In many cases, water could be used as the reaction medium without a cosolvent, and a variety of substituents R, such as keto, aldehyde, ester, free amine, and nitrile groups, remained intact during the transformation. Cy=cyclohexyl, Ms=methanesulfonyl, Ts=p-toluenesulfonyl.
- Yeung, Pui Yee,So, Chau Ming,Lau, Chak Po,Kwong, Fuk Yee
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supporting information; experimental part
p. 8918 - 8922
(2011/02/24)
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- Palladium-indolylphosphine-catalyzed hiyama cross-coupling of aryl mesylates
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(Chemical Equation Presented) Aryl mesylates are found to be applicable as electrophiles in organosilicon-mediated coupling reactions. The catalyst system comprising 2 mol % of Pd(OAc)2 and CM-phos supporting ligand is highly effective in catalyzing Hiyama cross-coupling of various aryl and heteroaryl mesylates. Interesting acid additive effects show that the presence of 0.25-0.50 equiv of acetic acid efficiently suppresses the mesylate decomposition and generally promotes the coupling product yields.
- So, Chau Ming,Lee, Hang Wai,Lau, Chak Po,Kwong, Fuk Yee
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supporting information; experimental part
p. 317 - 320
(2009/07/04)
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- A general palladium-catalyzed Suzuki-Miyaura coupling of aryl mesylates
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(Chemical Equation Presented) Catalyze this! The first palladium-catalyzed Suzuki-Miyaura coupling of unactivated aryl mesylates is reported, with not only arylboronic acids, but also other organoboron nucleophiles (see picture; Z=B(OH)2, BF3K, BPin). The reaction conditions are compatible with various common functional groups (R1=alkyl, OMe, CHO, CO, CN, CO2R′, heteroaryl).
- So, Chau Ming,Lau, Chak Po,Kwong, Fuk Yee
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supporting information; experimental part
p. 8059 - 8063
(2009/04/13)
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- NiCl2(dppe)-Catalyzed Cross-Coupling of Aryl Mesylates, Arenesulfonates, and Halides with Arylboronic Acids
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An investigation of the NiCl2(dppe)-, NiCl2(dppb)-, NiCl2(dppf)-, NiCl2(PCy3)2-, and NiCl2(PPh3)2- catalyzed cross-coupling of the previously unreported aryl mesylates, and of aryl arenesulfonates, chlorides, bromides, and iodides containing electron-withdrawing and electron-donating substituents with aryl boronic acids, in the absence of a reducing agent, is reported. NiCl2(dppe) was the only catalyst that exhibited high and solvent-independent activity in the two solvents investigated, toluene and dioxane. NiCl2(dppe) with an excess of dppe, NiCl 2(dppe)/dppe, was reactive in the cross-coupling of electron-poor aryl mesylates, tosylates, chlorides, bromides, and iodides. This catalyst was also efficient in the cross-coupling of aryl bromides and iodides containing electron-donating substituents. Most surprisingly, the replacement of the excess dppe from NiCl2(dppe)/dppe with excess PPh3 generated NiCl2(dppe)/PPh3, which was found to be reactive for the cross-coupling of both electron-rich and electron-poor aryl mesylates and chlorides. Therefore, the solvent-independent reactivity of NiCl2(dppe) provides an inexpensive and general nickel catalyst for the cross-coupling of aryl mesylates, tosylates, chlorides, bromides, and iodides with aryl boronic acids.
- Percec, Virgil,Golding, Geoffrey M.,Smidrkal, Jan,Weichold, Oliver
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p. 3447 - 3452
(2007/10/03)
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- Selected sulfonyl compounds as anticancer/antimalarial agents
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The synthesis and biological testing of a series of sulfonyl phenols and sulfonyl aryl methyl ethers has revealed that p-methoxyphenyl p-toluenesulfonate is a very selective and effective antimalarial agent which shows pronounced activity against human skin cancer cells. Application of a counter-attack strategy permits the direct preparation of the requisite tosylate ether from the bis(tosylate) of dihydroquinone.
- Langler, Richard F.,Paddock, Robert L.,Thompson, David B.,Crandall, Ian,Ciach, Michelle,Kain, Kevin C.
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p. 1127 - 1133
(2007/10/03)
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- Scope and limitation of the nickel-catalyzed coupling reaction between lithium borates and mesylates
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Coupling reaction of aryl borates and mesylates derived from phenols and enols was studied. Mesylates with an electron-with-drawing group or ring were highly reactive at room temperature in the presence of NiCl2(PPh3)2 to furnish the coupling products in good yields.
- Kobayashi, Yuichi,William, Anthony D.,Mizojiri, Ryo
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- A simple preparation of aryl methanesulfonates by thermal decomposition of dry arenediazonium O-benzenedisulfonimides in methanesulfonic acid
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Aryl methansulfonates 3 (18 examples) were easily prepared by thermal decomposition of dry arenediazonium o-benzenedisulfonimides 1 in methanesulfonic acid (2). The reactions were carried out at temperatures between 60 and 120°C for times between 0.5 and 8 h. The aryl methanesulfonates were obtained in reproducible yield of 70-90%, with few exceptions. In all cases the o-benzenedisulfonimide (4) could be recovered in good yields which can then be reused to prepare the salts 1. When thermal decomposition of salts 1 was carried out in trifluoromethanesulfonic acid (5) at 90-120°C for 1-2 h, aryl trifluoromethanesulfonates 6 were obtained in 73-78% yield (3 examples).
- Barbero, Margherita,Degani, Iacopo,Dughera, Stefano,Fochi, Rita,Perracino, Paolo
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- Aryl Mesylates in Metal-Catalyzed Homocoupling and Cross-Coupling Reactions. 1. Functional Symmetrical Biaryls from Phenols via Nickel-Catalyzed Homocoupling of Their Mesylates
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Aryl sulfonates including mesylate derived from phenols are converted in high yields to biaryls by homocoupling in the presence of catalytic amounts of zero-valent nickel catalysts generated in situ.This reaction provides the most convenient method for the synthesis of many functional symmetrical biaryls and was applied to the preparation of 2,2'-, 3,3'-, and 4,4'-disubstituted biphenyls and other biaryls.The influence of the electronic and steric effects of substituents attached in the ortho, meta, and para positions of aryl sulfonates and the nature of the sulfonate leaving group on the yield of homocoupled product as well as their influence on the extent of various side reactions were investigated.In addition, the influence of the effects of the polarity and dryness of solvent, halide ion source and concentration, and ratio of catalyst and ligand to aryl sulfonate are discussed.
- Percec, Virgil,Bae, Jin-Young,Zhao, Mingyang,Hill, Dale H.
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p. 176 - 185
(2007/10/02)
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- Sulphonate Esters as Sources of Sulphonyl Radicals; Ring-closure Reactions of Alk-4- and -5-enesulphonyl Radicals
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Alkyl alkanesulphonates and arenesulphonates were found to be useful sources of sulphonyl radicals, particularly for spectroscopic work, when treated with organotin or organosilyl radicals.Allyl, propynyl and penta-2,4-dienyl methanesulphonates gave, however, allyl, propynyl and pentadienyl radicals, respectively.Sulphonyl radicals generated in this way added efficiently to alk-1-enes with electron-releasing substituents, and the EPR spectra of the adduct radicals were recorded.A variety of radical initiation systems were tried on pent-4-enesulphonyl chloride.The pent-4-enesulphonyl radical cyclised mainly in the endo mode to give the six-membered-ring sulphone.Similarly, the hex-5-enesulphonyl radical cyclised to give thiepane 1,1-dioxide, with a seven-membered ring.The cyclohex-2-enylethanesulphonyl radical cyclised mainly in the exo mode to give 2-chloro-9-thiabicyclononane 9,9-dioxide.The mechanisms of these reactions are discussed.
- Culshaw, Peter N.,Walton, John C.
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p. 1201 - 1208
(2007/10/02)
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- MECHANISM OF THE REACTION OF (ARYLOXY)TRIMETHYLSTANNANE WITH METHANESULFONYL CHLORIDE - SOLVENT AND SUBSTITUENT EFFECTS ON THE RATE OF THE REACTION.
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A kinetic study has been conducted on the reactions of (aryloxy)trimethylstannanes with methanesulfonyl chloride giving chlorotrimethylstannane and aryl methanesulfonates. The reaction was found to obey a second order kinetic equation. The solvent effect on the rate of the reaction appeared obscure although a small rate enhancement was observed in a polar solvent. Substituent effect of the aryloxyl group was found to be dependent on the solvent used while a clear isokinetic relationship was observed. A charge separated four-center transition state has been suggested for the reaction.
- Kozuka,Yamaguchi,Tagaki
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p. 573 - 576
(2007/10/02)
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- ALKANESULFONYLATION REACTIONS IX. CATALYTIC EFFECT OF PYRIDINES ON THE MESYLATION OF PHENOLS
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The kinetics of the mesylation of seven substituted phenols in the presence of 13 derivatives of pyridine in benzene at 50 deg C were investigated.It was shown that in this case, in contrast to catalysis by trialkylamines, the elimination-addition (sulfen
- Skrypnik, Yu. G.,Bezrodnyi, V. P.
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p. 2056 - 2063
(2007/10/02)
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- THE MECHANISM OF THE REACTION OF ARYLOXYTRIMETHYLSTANNANE WITH METHANESULFONYL CHLORIDE
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A kinetic study has been conducted for the reaction of aryloxytrimethylstannane with methanesulfonyl chloride.Substituent effect was found to be dependent on the solvent and obscure solvent effect was observed.A mechanism has been suggested involving nearly concerted four-center transition state.
- Kozuka, Seizi,Yamaguchi, Shigeru,Tagaki, Waichiro
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p. 1299 - 1300
(2007/10/02)
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- ALKANESULFONYLATION REACTIONS. IV. MESYLATION OF PHENOLS IN THE PRESENCE OF TRIETHYLAMINE
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The kinetics of the acylation of five substituted phenols by methanesulfonyl chloride in the presence of triethylamine in benzene were investigated by GLC and potentiometric titration.The reaction is of first order in the sulfonyl chloride and triethylami
- Bezrodnyi, V. P.,Skrypnik, Yu. G.,Baranov, S. N.
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p. 1581 - 1586
(2007/10/02)
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