- Transition-Metal-Free DMAP-Mediated Aromatic Esterification of Amides with Organoboronic Acids
-
A new, transition-metal-free, effective method for aromatic esterification of amides with organoboronic acids has been developed. A wide range of benzoate derivatives were obtained with yields ranging from moderate to good. The catalytic reaction shows a broad substrate scope and excellent functional group tolerance. Conceptually, DMAP mediates the reaction and is crucial for this transformation.
- Guo, Jiarui,Liu, Lantao,Wang, Tao,Wang, Yanqing,Xu, Kai,Zhang, Yuheng
-
supporting information
p. 3274 - 3277
(2021/06/26)
-
- Rhodium-catalyzed synthesis of esters from aryl iodides and alcohols: use of alcohols with/without the assistance of aldehydes as carbon monoxide and nucleophile sources
-
A CO-gas-free rhodium-catalyzed alkoxycarbonylation of aryl iodide with alcohols has been developed. Alcohols, with/without the aid of an aldehyde, were used as a carbon monoxide and nucleophile source. The former synthesis afforded better yields of the alkoxycarbonylated products. Moreover, phenols also afforded phenoxycarbonylation products with high yields.
- Kim, Ju Hyun,Park, Hawon,Chung, Young Keun
-
p. 190 - 194
(2017/01/12)
-
- The heteropolyacid catalyzed phenol method for synthesizing Arylester
-
The invention discloses a synthesis method of phenol by aromatic esterification by using heteropoly acid as a catalyst. The method comprises the following steps: adding fatty acid substituted phenol ester I, substituted benzoic acid II, reaction solvent and heteropoly acid into a reaction vessel provided with a thermometer, a water separator and a stirrer, reacting at 110-170 DEG C for 0.5-10 hours, wherein the reaction progress is monitored by TLC (thin layer chromatography) in the reaction process; and after the reaction is finished, centrifuging the reaction solution, taking the supernate, washing to remove the solvent, and carrying out recrystallization or column chromatography on the crude product to obtain the aromatic ester compound III. By using the heteropoly acid as the catalyst, compared with the traditional esterification reaction, the method disclosed by the invention has the advantages of simple after-treatment, and low pollution and environment friendliness due to use of a small amount of acid. The heteropoly acid is a solid acid, and can be recycled by filtration after the reaction is finished. The aromatic esterification reaction of exchanging ester with phenol is adopted to avoid the side reaction caused by high oxidation tendency of the substituted phenol in the reaction, so that the method is simpler to operate and has higher yield.
- -
-
Paragraph 0054; 0055
(2016/11/09)
-
- Titanium superoxide-a stable recyclable heterogeneous catalyst for oxidative esterification of aldehydes with alkylarenes or alcohols using TBHP as an oxidant
-
Titanium superoxide efficiently catalysed the oxidative esterification of aldehydes with alkylarenes or alcohols, under truly heterogeneous conditions, to afford the corresponding benzyl and alkyl esters in excellent yields. Mechanistic studies have established that this "one pot" direct oxidative esterification process proceeds through a radical pathway, proven by a FTIR spectral study of a titanium superoxide-aldehyde complex as well as spin trapping experiments with TEMPO. The intramolecular version of this protocol has been successfully demonstrated in the concise synthesis of 3-butylphthalide, an anti-convulsant drug.
- Dey, Soumen,Gadakh, Sunita K.,Sudalai
-
p. 10631 - 10640
(2015/11/17)
-
- Ruthenium/NHC-catalyzed tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols
-
An efficient methodology to access benzoate derivatives via tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols catalyzed by ruthenium/NHC was developed. This operationally simple one-pot process uses O2 as the clean oxidant, producing esters in good to excellent yields.
- Zhang, Di,Pan, Changduo
-
experimental part
p. 41 - 45
(2012/06/18)
-
- Palladium/NHC-catalyzed tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols
-
A palladium/NHC-catalyzed tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols to access aryl benzoate derivatives is described. The procedure tolerates a series of functional groups, such as methoxy, nitro, cyano, chloro, fluoro and bromo groups. Thus, it represents a practically alternative method to access aryl benzoate derivatives.
- Luo, Fang,Pan, Changduo,Cheng, Jiang,Chen, Fan
-
supporting information; experimental part
p. 5878 - 5882
(2011/09/12)
-
- Palladium/NHC-catalyzed oxidative esterification of aldehydes with phenols
-
A palladium-catalyzed oxidative esterification of aldehydes with phenols is described, using air as the clean oxidant. This reaction tolerates many functional groups, providing esters with yields ranging from moderate to excellent.
- Zhang, Manli,Zhang, Shouhui,Zhang, Guoying,Chen, Fan,Cheng, Jiang
-
experimental part
p. 2480 - 2483
(2011/05/16)
-
- Investigation of a general base mechanism for ester hydrolysis in C-C hydrolase enzymes of the α/β-hydrolase superfamily: A novel mechanism for the serine catalytic triad
-
Previous mechanistic and crystallographic studies on two C-C hydrolase enzymes, Escherichia coli MhpC and Burkholderia xenovorans BphD, support a general base mechanism for C-C hydrolytic cleavage, rather than the nucleophilic mechanism expected for a ser
- Li, Jian-Jun,Bugg, Timothy D. H.
-
p. 507 - 513
(2008/03/28)
-
- Synthesis of novel nitro-substituted triaryl pyrazole derivatives as potential estrogen receptor ligands
-
Novel tetrasubstituted pyrazole derivatives bearing a nitro substituent on their A-phenol ring were synthesized and their binding affinity towards the estrogen receptor (ER) subtypes ERα and ERβ was determined. Among compounds tested, the 2-nitrophenol derivative 5c was found to bind satisfactorily to both estrogen receptor subtypes (RBAα=5.17 and RBAβ=3.27). In general, the introduction of a nitro group into the A ring of these compounds was found to benefit their ERβ binding abilities.
- Naoum, Fotini,Kasiotis, Konstantinos M.,Magiatis, Prokopios,Haroutounian, Serkos A.
-
p. 1259 - 1273
(2008/02/08)
-
- Kinetics of the reaction of 4-nitrophenyl benzoates with 4-chlorophenol in the presence of potassium carbonate in dimethylformamide
-
The effect of the substituent in the benzoyl group on the relative rate and activation parameters of transesterification of substituted 4-nitrophenyl benzoates with 4-chlorophenol in dimethylformamide in the presence of potassium carbonate was studied by the competing reaction technique. The whole series of benzoates showed the enthalpy-entropy compensation effect. 4-Nitrophenyl benzoates having electronacceptor substituents give rise to isokinetic relationship with an isokinetic temperature β of 382 K. The mechanism of the transesterification process is discussed. Pleiades Publishing, Inc., 2006.
- Os'kina,Vlasov
-
p. 865 - 872
(2007/10/03)
-
- Direct atom-efficient esterification between carboxylic acids and alcohols catalyzed by amphoteric, water-tolerant TiO(acac)2
-
A diverse array of oxometallic species were examined as catalysts for a test direct condensation of benzoic acid and 2-phenylethanol in 1:1 stoichiometry. Besides group IVB MOCl2-XH2O and TiOX 2-xH2O, group VB VOCl2-xTHF and group IVB TiO(acac)2 were found to be the most efficient and water-tolerant catalysts for the test reaction. The new neutral catalytic protocol with the optimal TiO(acac)2 tolerates many stereo/electronic structural variations in both (di)-acid (1°-3° alkyl and aryl) and (di)alcohol (1°, 2° alkyl, and aryl) components with high chemoselectivity.
- Chen, Chien-Tien,Munot, Yogesh S.
-
p. 8625 - 8627
(2007/10/03)
-
- Efficient method for the preparation of inverted alkyl carboxylates and phenyl carboxylates via oxidation-reduction condensation using 2,6-dimethyl-1,4-benzoquinone or simple 1,4-benzoquinone
-
Oxidation-reduction condensation using in situ formed alkoxydiphenylphosphines, 2,6-dimethy-1,4-benzoquinone, and carboxylic acids provides a useful method for the preparation of inverted tertiary alkyl carboxylates from the corresponding chiral tertiary alcohols under mild and neutral conditions. Similarly, it has afforded alkyl carboxylates successfully in good-to-high yields by the combined use of alkoxydiphenylphosphines having primary, secondary, or tertiary alkoxy groups, carboxylic acids, and simple 1,4-benzoquinone. When chiral secondary or tertiary alcohols are used, the corresponding inverted secondary or tertiary alkyl carboxylates are also obtained in good-to-high yields. In addition, a convenient method for the preparation of phenyl carboxylates in high yields has been established by utilizing oxidation-reduction condensation in toluene at 110 °C using phenoxydiphenylphosphines in situ-formed from phenols and chlorodiphenylphosphine, 2,6-dimethyl-1,4-benzoquinone, and carboxylic acids.
- Shintou, Taichi,Fukumoto, Kentaro,Mukaiyama, Teruaki
-
p. 1569 - 1579
(2007/10/03)
-
- Pd-catalyzed decarbonylative olefination of aryl esters: Towards a waste-free Heck reaction
-
Easy and clean: A palladium (0)-catalyzed decarbonylative Heck olefination of activated esters of aryl, heteroaryl, and vinyl carboxylic acids opens up an opportunity for a novel waste-free Heck olefination process (see scheme).
- Goossen, Lukas J.,Paetzold
-
p. 1237 - 1241
(2007/10/03)
-
- The chemoselective preparation of the substituted phenyl benzoates using re-Y zeolite as catalyst
-
A practical and chemoselective method for the synthesis of substituted phenyl benzoates using rare earth zeolite as catalyst was described, its recycle procedure offers high total yield.
- Ding, Yixiang,Wu, Rui,Lin, Qiang
-
p. 2149 - 2153
(2007/10/03)
-
- Triarylpyrazoles with basic side chains: Development of pyrazole-based estrogen receptor antagonists
-
Recently, we developed a novel triaryl-substituted pyrazole ligand system that has high affinity for the estrogen receptor (ER) (Fink, B. E.; Mortenson, D. S.; Stauffer, S. R.; Aron, Z. D.; Katzenellenbogen, J. A. Chem. Biol. 1999, 6, 205). Subsequent wor
- Stauffer, Shaun R.,Huang, Ying R.,Aron, Zachary D.,Coletta, Christopher J.,Sun, Jun,Katzenellenbogen, Benita S.,Katzenellenbogen, John A.
-
p. 151 - 161
(2007/10/03)
-
- Pyrazole ligands: Structure - Affinity/activity relationships and estrogen receptor-α-selective agonists
-
We have found that certain tetrasubstituted pyrazoles are high-affinity ligands for the estrogen receptor (ER) (Fink et al. Chem. Biol. 1999, 6, 205-219) and that one pyrazole is considerably more potent as an agonist on the ERα than on the ERβ subtype (Sun et al. Endocrinology 1999, 140, 800-804). To investigate what substituent pattern provides optimal ER binding affinity and the greatest enhancement of potency as an ERα-selective agonist, we prepared a number of tetrasubstituted pyrazole analogues with defined variations at certain substituent positions. Analysis of their binding affinity pattern shows that a C(4)-propyl substituent is optimal and that a p-hydroxyl group on the N(1)-phenyl group also enhances affinity and selectivity for ERα. The best compound in this series, a propylpyrazole triol (PPT, compound 4g), binds to ERα with high affinity (ca. 50% that of estradiol), and it has a 410-fold binding affinity preference for ERα. It also activates gene transcription only through ERα. Thus, this compound represents the first ERα-specific agonist. We investigated the molecular basis for the exceptional ERα binding affinity and potency selectivity of pyrazole 4g by a further study of structure-affinity relationships in this series and by molecular modeling. These investigations suggest that the pyrazole triols prefer to bind to ERα with their C(3)-phenol in the estradiol A-ring binding pocket and that binding selectivity results from differences in the interaction of the pyrazole core and C(4)-propyl group with portions of the receptor where ERα has a smaller residue than ERβ. These ER subtype-specific interactions and the ER subtype-selective ligands that can be derived from them should prove useful in defining those biological activities in estrogen target cells that can be selectively activated through ERα.
- Stauffer,Coletta,Tedesco,Nishiguchi,Carlson,Sun,Katzenellenbogen,Katzenellenbogen
-
p. 4934 - 4947
(2007/10/03)
-
- The Reactivity of p-Nitrophenyl Esters with Surfactants in Apolar Solvents. VII. Substituent Effects on the Reactivity of 4'-Nitrophenyl 4-Substituted Benzoates in Benzene Solutions of Dodecylammonium Propionate and Butane-1,4-diamine Bis(dodecanoate)
-
The rate of decomposition of a series of 4'-nitrophenyl 4-substituted benzoates has been measured at 341 K in benzene solutions of dodecylammonium propionate and butane-1,4-diamine bis(dodecanoate).The bimolecular rate constant due to general acid-general
- O'Connor, Charmian J.,Lomax, Terence D.
-
p. 917 - 925
(2007/10/02)
-