- Isothiourea-Catalysed Regioselective Acylative Kinetic Resolution of Axially Chiral Biaryl Diols
-
An operationally simple isothiourea-catalysed acylative kinetic resolution of unprotected 1,1′-biaryl-2,2′-diol derivatives has been developed to allow access to axially chiral compounds in highly enantioenriched form (s values up to 190). Investigation of the reaction scope and limitations provided three key observations: i) the diol motif of the substrate was essential for good conversion and high s values; ii) the use of an α,α-disubstituted mixed anhydride (2,2-diphenylacetic pivalic anhydride) was critical to minimize diacylation and give high selectivity; iii) the presence of substituents in the 3,3′-positions of the diol hindered effective acylation. This final observation was exploited for the highly regioselective acylative kinetic resolution of unsymmetrical biaryl diol substrates bearing a single 3-substituent. Based on the key observations identified, acylation transition state models have been proposed to explain the atropselectivity of this kinetic resolution.
- Qu, Shen,Greenhalgh, Mark D.,Smith, Andrew D.
-
supporting information
p. 2816 - 2823
(2019/02/05)
-
- Cu-MOF: An efficient heterogeneous catalyst for the synthesis of symmetric anhydrides: Via the C-H bond activation of aldehydes
-
In this paper, an efficient and straightforward synthetic approach for the preparation of a number of symmetric carboxylic anhydrides was reported using Cu2(BDC)2(DABCO) as an efficient heterogeneous catalyst via the C-H bond activation of aldehydes with excellent yields and simple work up. This C-H bond activation reaction appears simple and convenient, has a wide substrate scope and makes use of cheap, abundant, and easily available reagents. The Cu-MOF catalyst was recycled and reused four times without any loss of catalytic activity.
- Ahmadzadeh, Zahra,Mokhtari, Javad,Rouhani, Morteza
-
p. 24203 - 24208
(2018/07/25)
-
- Synthesis, molecular docking, and pharmacological evaluation of N-(2-(3,5-dimethoxyphenyl)benzoxazole-5-yl)benzamide derivatives as selective COX-2 inhibitors and anti-inflammatory agents
-
A series of N-(2-(3,5-dimethoxyphenyl)benzoxazole-5-yl)benzamide derivatives (3am) was synthesized and evaluated for their in vitro inhibitory activity against COX-1 and COX-2. The compounds with considerable in vitro activity (IC50 50 values in the range of 0.06–0.71 μM. The in vivo anti-inflammatory activity of these six compounds (3a, 3b, 3d, 3g, 3j, and 3k) was assessed by the carrageenan-induced rat paw edema method. Compounds 3d (84.09%), 3g (79.54%), and 3a (70.45%) demonstrated significant anti-inflammatory activity compared to the standard drug ibuprofen (65.90%) and were also found to be safer than ibuprofen, by ulcerogenic studies. A docking study was done using the crystal structure of human COX-2, to understand the binding mechanism of these inhibitors to the active site of COX-2.
- Kaur, Avneet,Pathak, Dharam P.,Sharma, Vidushi,Wakode, Sharad
-
-
- Synthesis, biological evaluation and docking study of a new series of di-substituted benzoxazole derivatives as selective COX-2 inhibitors and anti-inflammatory agents
-
A new series of substituted-N-(3,4-dimethoxyphenyl)-benzoxazole derivatives 13a–13p was synthesized and evaluated in vitro for their COX (I and II) inhibitory activity, in vivo anti-inflammatory and ulcerogenic potential. Compounds 13d, 13h, 13k, 13l and 13n exhibited significant COX-2 inhibitory activity and selectivity towards COX-2 over COX-1. These selected compounds were screened for their in vivo anti-inflammatory activity by carrageenan induced rat paw edema method. Among these compounds, 13d was the most promising analogs of the series with percent inhibition of 84.09 and IC50 value of 0.04 μM and 1.02 μM (COX-2 and COX-1) respectively. Furthermore, ulcerogenic study was performed and tested compounds (13d, 13h, 13k, 13l) demonstrated a significant gastric tolerance than ibuprofen. Molecular docking study was also performed with resolved crystal structure of COX-2 to understand the binding mechanisms of newly synthesized inhibitors in the active site of COX-2 enzyme and the results were found to be concordant with the biological evaluation studies of the compounds. These newly synthesized inhibitors also showed acceptable pharmacokinetic profile in the in silico ADME/T analyses.
- Kaur, Avneet,Pathak, Dharam P.,Sharma, Vidushi,Wakode, Sharad
-
p. 891 - 902
(2018/01/22)
-
- Synthesis, biological evaluation and docking study of N-(2-(3,4,5-trimethoxybenzyl)benzoxazole-5-yl) benzamide derivatives as selective COX-2 inhibitor and anti-inflammatory agents
-
A series of N-(2-(3,4,5-trimethoxybenzyl)-benzoxazole-5-yl)benzamide derivatives (3a–3n) was synthesized and evaluated for its in vitro inhibitory activity against COX-1 and COX-2. The compounds with considerable in vitro activity (IC50 50 in the range of 0.14–0.69 μM. In vivo anti-inflammatory activity of these six compounds (3b, 3d, 3e, 3h, 3l and 3m) was assessed by carrageenan induced rat paw edema method. The compound 3b (79.54%), 3l (75.00%), 3m (72.72%) and 3d (68.18%) exhibited significant anti-inflammatory activity than standard drug ibuprofen (65.90%). Ulcerogenic activity with histopathological studies was performed, and the screened compounds demonstrated significant gastric tolerance than ibuprofen. Molecular Docking study was also performed with resolved crystal structure of COX-2 to understand the interacting mechanisms of newly synthesized inhibitors with the active site of COX-2 enzyme and the results were found to be in line with the biological evaluation studies of the compounds.
- Kaur, Avneet,Pathak, Dharam P.,Sharma, Vidushi,Narasimhan, Balasubramanian,Sharma, Prateek,Mathur, Rajani,Wakode, Sharad
-
p. 191 - 202
(2018/08/23)
-
- Synthesis, cyclooxygenase-2 inhibition, anti-inflammatory evaluation and docking study of substituted-n-(3,4,5-trimethoxyphenyl)-benzo[d]oxazole derivatives
-
Background: Non-steroidal anti-inflammatory drugs are widely used for many years, but the chronic use of NSAID’s leads to gastric side effects, ulceration and kidney problems. These side effects are due to non-selective inhibition of COX-2 along with COX-1. Therefore, it is imperative to develop novel and selective COX-2 inhibitors. Objective: In this paper wehave synthesized a series of novel hybrids comprising of substituted-N-(3,4,5-trimethoxyphenyl)-benzo[d]oxazole derivatives and screened for the treatment of inflammation. Methods: The structures of the obtained compounds were elucidated by elemental and spectral analysis (ATR-FTIR,1 H NMR,13 C NMR, Mass spectroscopy). All of the compounds were evaluated for cyclooxygenase (COX-1/COX-2) inhibitory activity by in vitro enzymatic assay. The compound which showed COX-2 activity (3a-3e, 3g – 3h, 3k, 3m and 3o) was further screened for in vivo anti-inflammatory activity and ulcerogenic liability. Molecular docking study was also performed with resolved crystal structure of COX-2 to understand the binding mechanism of newly synthesized inhibitors in the active site of COX-2enzyme. Results: The in vitro COX-1 and COX-2 inhibitory studies showed that the synthesized compounds potentially inhibited COX-2 (IC50 = 0.04 – 26.41 μM range) over COX-1 (IC50 = 0.98 – 33.33 μM range). The in vivo studies predicted that compounds 3c (70.9%, 0.6±0.22), 3m (68.1%, 1.9±0.41) and 3o (70.4%, 1.7±0.27) produced more efficacy against carrageenan induced paw edema and less ulcerogenic effect, as compared to standard ibuprofen (65.9%, 2.2±0.44). The results of docking studies were found to be concordant with the biological evaluation studies of the prepared compound. Conclusion: Among all the tested compounds, 2-Chloro-N-(2-(3,4,5-trimethoxyphenyl)-benzo[d]oxazol-5-yl)-benzamide (3c) was the most potent anti-inflammatory agent and has less ulcerogenic potential. This series of compound can be explored more for development of safer and more active anti-inflammatory agents.
- Kaur, Avneet,Wakode, Sharad,Pathak, Dharam P.,Sharma, Vidushi,Shakya, Ashok K.
-
p. 660 - 673
(2018/11/06)
-
- Facile and direct synthesis of symmetrical acid anhydrides using a newly prepared powerful and efficient mixed reagent
-
An efficient mixed reagent for direct synthesis of symmetrical carboxylic anhydrides from carboxylic acids has been prepared. Carboxylic acids are converted to anhydrides using triphenylphosphine/ trichloroisocyanuric acid under mild reaction conditions at room temperature. Short reaction time, excellent yields of products, low cost, availability of reagents, simple experimental procedure, and easy work-up of the products are the main advantages of the presented method.
- Rouhi-Saadabad, Hamed,Akhlaghinia, Batool
-
p. 479 - 485
(2015/01/30)
-
- Iron-doped single-walled carbon nanotubes as new heterogeneous and highly efficient catalyst for acylation of alcohols, phenols, carboxylic acids and amines under solvent-free conditions
-
Iron-doped single-walled carbon nanotubes (Fe/SWCNTs) represent an efficient and new heterogeneous reusable catalyst for the acylation of a variety of alcohols, phenols, carboxylic acids and amines with acid chlorides or acid anhydrides under solvent-free conditions. The reactions of various primary, secondary, tertiary, and benzylic alcohols, diols, phenols, as well as aromatic and aliphatic amines give acylated adducts in good to excellent yields.
- Sharghi, Hashem,Jokar, Mahboubeh,Doroodmand, Mohammad Mahdi
-
experimental part
p. 426 - 442
(2011/04/15)
-
- Efficient and convenient synthesis of symmetrical carboxylic anhydrides from carboxylic acids with sulfated zirconia by phase transfer catalysis
-
An efficient and convenient procedure for the synthesis of symmetrical carboxylic anhydrides from carboxylic acids with sulfated zirconia by PEG-1000 phase transfer catalysis has been developed. The reactions proceeded under mild and solvent-free conditions to provide the carboxylic anhydrides in good to excellent yields. The product can be isolated by a simple extraction with organic solvent, and the catalyst system can be recycled or reused without any significant loss of catalytic activity.
- Hu, Yu Lin,Zhao, Xing E.,Lu, Ming
-
experimental part
p. 255 - 262
(2012/04/17)
-
- Total synthesis and structural revision of vannusals A and B: Synthesis of the true structures of vannusals A and B
-
Having determined through total synthesis that the originally assigned structure of vannusals A and B were incorrect, we set out to uncover the identity of the true structures of these novel marine natural products. Our search was based on intelligence gathered by NMR spectroscopy and chemical synthesis and took us through the total synthesis of eight diastereomeric vannusal B structures [2, d-2, 3, d-3, 4, d-4, 5, and d-5, Figure 2]. The true structures of vannusals A and B were finally determined to be d-5 and d-1, respectively. Their total synthesis was based on a highly convergent and efficient strategy that involved fragments vinyl iodide (-)-6 and aldehyde (±)-94, and featured a stereoselective lithium-mediated coupling reaction and a samarium-induced cyclization process that forged the final ring of the carbon framework. The synthetic strategies and technologies developed in these investigations expand the scope of chemical synthesis and render these compounds readily available for biological evaluation, while the NMR spectroscopic insights gained should prove useful in future structural determination endeavors.
- Nicolaou,Ortiz, Adrian,Zhang, Hongjun,Guella, Graziano
-
supporting information; experimental part
p. 7153 - 7176
(2010/07/09)
-
- A mild, clean, and simple synthesis of symmetrical carboxylic anhydrides from carboxylic acides using a polymer supported tosyl chloride
-
The use of polymeric reagents simplifies routine acylation of carboxylic acid because it eliminates the traditional purification. We describe the use of readily available cross-linked poly(4-vinylpyridine) supported tosyl chloride, [P4VP].TsCl, in the suspended solution phase synthesis of symmetrical anhydrides from carboxylic acids in the presence of K2CO3 in high yields and purity. The products can be obtained by filtration and evaporation of the solvent.
- Zarchi, M. A. Karimi,Mirjalili,Kahrizsangi, Z. Shamsi,Tayefi
-
experimental part
p. 455 - 460
(2010/08/20)
-
- Effective esterification of carboxylic acids using (6-oxo-6H-pyridazin-1-yl)phosphoric acid diethyl ester as novel coupling agents
-
(6-Oxo-6H-pyridazin-1-yl)phosphoric acid diethyl esters (3) are efficient and selective coupling agents for equimolar esterification of carboxylic acids and alcohols. Esterification of aliphatic and aromatic carboxylic acids with aliphatic and aromatic alcohols using 3 afforded the corresponding esters chemoselectively in good to excellent yield.
- Won, Ju-Eun,Kim, Ho-Kyun,Kim, Jeum-Jong,Yim, Heong-Seup,Kim, Min-Jung,Kang, Seung-Beom,Chung, Hyun-A.,Lee, Sang-Gyeong,Yoon, Yong-Jin
-
p. 12720 - 12730
(2008/03/14)
-
- Access to a new family of medium ring aromatic lactones
-
We report a new method for preparation of hydroxyacids as precursors of benzolactones using a simple and an efficient electrochemical step. This gives in only four steps six- to eleven-membered lactones with high isolated yields from conveniently substituted aryl bromides. The lactonisation was performed according to the Yamamoto's process.
- Métay, Estelle,Léonel, Eric,Condon, Sylvie,Nédélec, Jean-Yves
-
p. 8515 - 8524
(2007/10/03)
-
- Investigation of the Yamaguchi esterification mechanism. Synthesis of a Lux-S enzyme inhibitor using an improved esterification method
-
(Chemical Equation Presented) A one-pot procedure for the regioselective synthesis of aliphatic esters is described. This was a result of a study on mixed aliphatic-aromatic anhydrides. The data suggest that during the Yamaguchi esterification reaction, a symmetric aliphatic anhydride is produced in situ, which upon reaction with an alcohol yields the ester. We confirmed that benzoyl chloride could be used instead of the sterically hindered Yamaguchi acid chloride. This method was successfully applied in the synthesis of Lux-S aspartic acid inhibitor.
- Dhimitruka, Ilirian,SantaLucia Jr., John
-
-
- Synthesis of precursors for medium-ring aromatic lactones
-
Hydroxyacids have been prepared via the nickel-catalysed electrochemical arylation of ethyl acrylate from an ortho-substituted aryl bromide. Protection and deprotection steps have been selected in terms of suitability and efficiency. The lactonisation was
- Metay, Estelle,Leonel, Eric,Sulpice-Gaillet, Christine,Nedelec, Jean-Yves
-
p. 1682 - 1688
(2007/10/03)
-
- PROCESS FOR PRODUCING ACID ANHYDRIDE
-
According to the present invention there is provided a process for producing an acid anhydride by reacting a carboxylic acid, preferably a carboxylic acid having a polymerizable group, with a sulfonyl halide compound in the presence of a tertiary amine or in the presence of a tertiary amine and an inorganic base, wherein the tertiary amine or the tertiary amine and the inorganic base are used in an amount of 0.9 to 1.2 equivalents relative to the acid generated from the sulfonyl halide compound.
- -
-
-
- A Cheap, Simple and Efficient Method for the Preparation of Symmetrical Carboxylic Acid Anhydrides
-
A manipulatively simple and facile one-pot procedure for the synthesis of symmetrical anhydride is reported. Treatment of carboxylic acids with tosyl chloride in K2CO3 media under solvent free conditions gives the corresponding anhydrides in good to excellent yields in a short reaction time via carboxylic sulfonic anhydride as the key intermediate.
- Kazemi, Foad,Sharghi, Hashem,Nasseri, Mohammad Ali
-
p. 205 - 207
(2007/10/03)
-
- Dabco/SOCl2, mild, and convenient reagent for the preparation of symmetrical carboxylic acid anhydrides
-
Various types of carboxylic acids undergo rapid dehydration with 1,4-diazabicyclo[2.2.2]octane, dabco / thionyl chloride, under mild reaction conditions to afford symmetrical acid anhydrides in high isolated yields.
- Kazemi, Foad,Kiasat, Ali Reza
-
p. 2287 - 2291
(2007/10/03)
-
- An efficient and simple procedure for preparation of esters and anhydrides from acid chlorides in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) under solvent-free conditions
-
A manipulatively one-pot and rapid method for the synthesis of aliphatic and aromatic ester and anhydride from acid chloride and alcohol or potassium salt of carboxylic acid under solvent-free conditions is reported. The reaction has been carried out in excellent yield and short reaction time in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) under solvent-free conditions.
- Hajipour,Mazloumi
-
-
- A convenient method for synthesis of symmetrical acid anhydrides from carboxylic acids with trichloroacetonitrile and triphenylphosphine
-
Various carboxylic acids are converted into the corresponding carboxylic acid anhydrides treated with trichloroacetonitrile and triphenylphosphine in the presence of triethylamine at room temperature.
- Kim,Jang
-
p. 395 - 399
(2007/10/03)
-
- A convenient method for the synthesis and one-pot reaction of acyl chlorides using a scavenging resin
-
A simple, efficient and fast method for the preparation of acyl halides from fatty carboxylic acids using a solid phase scavenging approach is presented herein. The title compounds can then be isolated, used as a solution or react in one-pot to form esters and amides with good to excellent yields.
- Girard,Tranchant,Niore,Herscovici
-
p. 1577 - 1580
(2007/10/03)
-
- A facile synthesis of acid anhydrides
-
A facile synthesis of symmetric and unsymmetric acid anhydrides using phase-transfer catalysis is described. By this method different types of anhydrides can be obtained in high yields under mild conditions even on microscale levels.
- Dubey,Kumar, R. Vinod
-
-
- Allylic amidation of olefins by ene reaction of acylnitroso compounds generated in situ by oxidation of hydroxamic acids
-
A one-pot allylic amidation procedure, which employs the ene reaction of acylnitroso compounds 2 with electron-rich olefins 3a,b, is presented; the acylnitroso enophile is generated in situ by oxidation of hydroxamic acids 1 with iodosobenzene diacetate.
- Adam, Waldemar,Bottke, Nils,Krebs, Oliver,Saha-Moeller, Chantu R.
-
p. 1963 - 1965
(2007/10/03)
-
- Synthesis of anhydrides from acyl chlorides under ultrasound condition
-
A convenient and general method for the synthesis of symmetrical anhydrides under ultrasound conditions is described.
- Hu, Yulai,Wang, Jin-Xian,Li, Shihua
-
p. 243 - 248
(2007/10/03)
-
- The formation of anhydrides in the Mitsunobu reaction
-
Treatment of benzoic acid with triphenylphosphine and diisopropyl azodicarboxylate in THF or acetonitrile, results in the formation of benzoic anhydride. A significant solvent effect was observed for this reaction. Anhydride formation did not occur however with the more acidic p-nitrobenzoic acid. Relative rate and competition experiments suggest that the improved yields observed when p-nitrobenzoic acid is used instead of benzoic acid in the Mitsunobu esterification reaction are due to competitive anhydride formation in the latter case.
- Harvey, Peta J.,Von Itzstein, Mark,Jenkins, Ian D.
-
p. 3933 - 3942
(2007/10/03)
-
- Scandium trifluoromethanesulfonate as an extremely active Lewis acid catalyst in acylation of alcohols with acid anhydrides and mixed anhydrides
-
Scandium trifluoromethanesulfonate (triflate), which is commercially available, is a practical and useful Lewis acid catalyst for acylation of alcohols with acid anhydrides or the esterification of alcohols by carboxylic acids in the presence of p-nitrobenzoic anhydrides. The remarkably high catalytic activity of scandium triflate can be used for assisting the acylation by acid anhydrides of not only primary alcohols but also sterically-hindered secondary or tertiary alcohols. The method presented is especially effective for selective macrolactonization of ω-hydroxy carboxylic acids.
- Ishihara, Kazuaki,Kubota, Manabu,Kurihara, Hideki,Yamamoto, Hisashi
-
p. 4560 - 4567
(2007/10/03)
-
- Solid-liquid phase transfer and cobalt or palladium complex catalyzed synthesis of anhydrides from acyl chlorides
-
Acyl chloride can efficiently be converted into anhydride under solid liquid phase transfer catalysis by using bis(triphenylphosphine)cobalt dichloride or bis (triphenylphospine)palladium dichloride as catalyst.
- Wang,Hu,Cui
-
p. 3261 - 3268
(2007/10/02)
-
- COBALT(II) CHLORIDE CATALYZED SYNTHESES OF ACID ANHYDRIDES FROM ACID CHLORIDES
-
Acid anhydrides were synthesized by reacting acid chlorides with carboxylic acids in the presence of catalytic quantities of cobalt(II) chloride.
- Srivastava, Rajiv R.,Kabalka, George W.
-
p. 593 - 594
(2007/10/02)
-
- Hydroxy protection groups
-
The present invention concerns a method for preparing unprotected hydroxy compounds or acylated derivatives thereof by conversion of silyl alkyl-protected hydroxy compounds. The invention also relates to novel intermediates useful in the method and for other purposes.
- -
-
-
- A NEW SYNTHESIS OF CARBOXYLIC AND CARBONIC ACID ANHYDRIDES USING PHASE TRANSFER REACTIONS
-
Acyl chlorides and alkylchloroformates smoothly reacted with one molar equivalent of sodium hydroxide, using liquid-liquid phase transfer conditions to afford high yields of the corresponding symmetrical carboxylic and carbonic hemiester anhydrides.Unstable anhydrides such as 4-nitrobenzoic, 2-furoic and methacrylic anhydrides, which are otherwise difficult to obtain, were easily prepared by this method.The reaction mechanism does not seem to involve intermediate hydrolysis of half the acid chloride into the corresponding sodium carboxylate.
- Plusquellec, Daniel,Roulleau, Fabienne,Lefeuvre, Martine,Brown, Eric
-
p. 2471 - 2476
(2007/10/02)
-
- A Convenient One-Pot Synthesis of Carboxylic Acid Anhydrides Using 1,1'-Oxalyldiimidazole
-
Aliphatic, aromatic, and heteroaromatic carboxylic acids (5a-i) react with 1,1'-oxalyldiimidazole (6) in acetonitrile under reflux in the presence of methanesulfonic acid (12) to give the corresponding carboxylic acid anhydrides (9a-i) in 30-98percent yields.Keywords- dehydration; carboxylic acid anhydride; N-acylimidazole; 1,1'-carbonyldiimidazole; 1,1'-oxalyldiimidazole
- Kitagawa, Tokujiro,Kuroda, Hiroko,Sasaki, Hideaki
-
p. 1262 - 1265
(2007/10/02)
-
- REAGENTS AND SYNTHETIC METHODS 25. A NEW METHOD FOR THE SYNTHESIS OF ACYL AZIDES FROM CARBOXYLIC ACIDS AND SODIUM AZIDE INDUCED BY PHENYL DICHLOROPHOSPHATE.
-
Carbonyl azides are obtained in high yields by one-pot method from carboxylic acids and sodium azide by means of phenyl dichlorophosphates reagent.
- Lago, J. M.,Arrieta, A.,Palomo, C.
-
p. 289 - 296
(2007/10/02)
-
- REAGENTS AND SYNTHETIC METHODS 28. MODIFIED PROCEDURES FOR ANHYDRIZATION, ESTERIFICATION AND THIOLESTERIFICATION OF CARBOXYLIC ACIDS BY MEANS OF AVAILABLE PHOSPHORUS REAGENTS.
-
Carboxylic acid anhydrides, esters and thiol esters are obtained by a one-pot method from carboxylic acids and alcohols or thiol by means of phosphorus oxychloride or phenyl dichlorophosphoridate reagents.
- Arrieta, A.,Garcia, T.,Lago, J. M.,Palomo, C.
-
p. 471 - 488
(2007/10/02)
-
- p-Methoxybenzoyl p-Nitrobenzoyl Peroxide Revisited: Catalysis by Silica
-
The decomposition of p-methoxybenzoyl p-nitrobenzoyl peroxide (1) in benzene/silica slurries at room temperature is faster than in benzene solution by 5 orders of magnitude.The first product of the reaction is entirely or mainly the carboxy inversion compound, p-methoxyphenyl p-nitrobenzoyl carbonate (2), which also decomposes on the silica.The products from experiments in which 2 is the initial reagent are the same as those from the peroxide.The most important are p-methoxyphenyl p-nitrobenzoate, p-methoxyphenol, and p-nitrobenzoic acid.The absence within the limits of GC/MS of anisic acid, p-methoxybiphenyl, p-nitrobiphenyl, p-nitrophenyl anisate, p-methoxy-p'-nitrobiphenyl, phenyl p-nitrobenzoate, phenyl anisate, and phenyl p-nitrobenzoate indicates that the decomposition of 1 under these conditions produces no free radicals.
- Leffler, John E.,Barbas, John T.,Flowers, G. Craig
-
p. 2286 - 2287
(2007/10/02)
-
- Mechanism for Diacyl Peroxide Decomposition
-
The presence of ion-pair intermediates in diacyl peroxide decomposition has been established.Various substituted (4-X-phenyl)phenylacetyl Y-benzoyl peroxides and three corresponding 4-X-benzhydryl-4-nitrobenzoic carbonic anhydrides (X = CH3, H, Cl) were prepared.All compounds decomposed in 90percent acetone-water (v/v), giving the ionic products ester, alkohol, and acid.The fraction of ester (R) was similar to that found in the solvolysis of substituted benzhydryl-N-nitrosoamides, indicating a similar spectrum of ion-pair intermediates.The yield of ester product could be increased markedly by the addition of common ion.The mixed carbonic carboxylic anhydrides were not products of peroxide decomposition in either nucleophilic or nonnucleophilic solvents and showed a lower decompositin rate than the peroxide.Lastly, both the peroxide and the mixed carbonic carboxylic anhydride decomposed in chloroform with net retention.Neither CIDNP nor any radical abstraction product was detected.
- Linhardt, R.J.,Murr, B.L.,Montgomery, E.,Osby, J.,Sherbine, J.
-
p. 2242 - 2251
(2007/10/02)
-
- Reaction of Diazonium Salts with Transition Metals. 6. Preparation of Mixed Acid Anhydrides from Arenediazonium Salts and Sodium Carboxylates under Palladium(0) Catalysis
-
The palladium(0)-catalyzed reaction of arenediazonium tetrafluoroborates with carbon monoxide and sodium carboxylates in acetonitrile at 25 deg C gave mixed acid anhydrides, ArCOOCOR (Ar = 3-Me-Ph, 4-Me-Ph, 2-MeO-Ph, 4-Br-Ph, 4-I-Ph, 3-NO2-Ph, 4-NO2-Ph, and Ph; R = H, Me, Et, t-Bu, and Ph) in good yields.Homoaromatic acid anhydrides, (ArCO)2O, were obtained by heating of ArCOOCOMe at 100-120 deg C under vacuum.ArCOOCO-t-Bu can be utilized to obtain the corresponding arenecarboxamides by the reaction with some amines.
- Kikukawa, Kiyoshi,Kono, Kiyoshi,Nagira, Kazuhiko,Wada, Fumio,Matsuda, Tsutomu
-
p. 4413 - 4416
(2007/10/02)
-
- NOVEL TRANSFORMATION OF ARENEDIAZONIUM SALTS TO ACID ANHYDRIDES UNDER PALLADIUM CATALYSIS
-
Palladium catalyzed reaction of arenediazonium salts, carbon monoxide and sodium carboxylates gave mixed anhydrides, wich in turn could be converted to aromatic acid anhydrides in good yields.
- Kikukawa, Kiyoshi,Kono, Kiyoshi,Nagira, Kazuhiko,Wada, Fumio,Matsuda, Tsutomu
-
p. 2877 - 2878
(2007/10/02)
-