828-51-3Relevant articles and documents
Mechanochemical Grignard Reactions with Gaseous CO2 and Sodium Methyl Carbonate**
Pfennig, Victoria S.,Villella, Romina C.,Nikodemus, Julia,Bolm, Carsten
supporting information, (2022/01/22)
A one-pot, three-step protocol for the preparation of Grignard reagents from organobromides in a ball mill and their subsequent reactions with gaseous carbon dioxide (CO2) or sodium methyl carbonate providing aryl and alkyl carboxylic acids in up to 82 % yield is reported. Noteworthy are the short reaction times and the significantly reduced solvent amounts [2.0 equiv. for liquid assisted grinding (LAG) conditions]. Unexpectedly, aryl bromides with methoxy substituents lead to symmetric ketones as major products.
Cleavage of Carboxylic Esters by Aluminum and Iodine
Sang, Dayong,Yue, Huaxin,Fu, Yang,Tian, Juan
, p. 4254 - 4261 (2021/03/09)
A one-pot procedure for deprotecting carboxylic esters under nonhydrolytic conditions is described. Typical alkyl carboxylates are readily deblocked to the carboxylic acids by the action of aluminum powder and iodine in anhydrous acetonitrile. Cleavage of lactones affords the corresponding ω-iodoalkylcarboxylic acids. Aryl acetylates undergo deacetylation with the participation of the neighboring group. This method enables the selective cleavage of alkyl carboxylic esters in the presence of aryl esters.
Acetyl nitrate mediated conversion of methyl ketones to diverse carboxylic acid derivatives
Bernard, Josephine,Capilato, Joseph N.,Hoy, Erik P.,Mattiucci, Joseph,Pellegrinelli, Peter J.,Perez, Lark J.,Philippi, Shane,Schnorbus, Logan
, p. 5298 - 5302 (2021/06/30)
The development of a novel acetyl nitrate mediated oxidative conversion of methyl ketones to carboxylic acid derivatives is described. By analogy to the haloform reaction and supported by experimental and computational investigation we propose a mechanism for this transformation.
Suppressing carboxylate nucleophilicity with inorganic salts enables selective electrocarboxylation without sacrificial anodes
Corbin, Nathan,Lazouski, Nikifar,Manthiram, Karthish,Steinberg, Katherine,Yang, Deng-Tao
, p. 12365 - 12376 (2021/10/08)
Although electrocarboxylation reactions use CO2as a renewable synthon and can incorporate renewable electricity as a driving force, the overall sustainability and practicality of this process is limited by the use of sacrificial anodes such as magnesium and aluminum. Replacing these anodes for the carboxylation of organic halides is not trivial because the cations produced from their oxidation inhibit a variety of undesired nucleophilic reactions that form esters, carbonates, and alcohols. Herein, a strategy to maintain selectivity without a sacrificial anode is developed by adding a salt with an inorganic cation that blocks nucleophilic reactions. Using anhydrous MgBr2as a low-cost, soluble source of Mg2+cations, carboxylation of a variety of aliphatic, benzylic, and aromatic halides was achieved with moderate to good (34-78%) yields without a sacrificial anode. Moreover, the yields from the sacrificial-anode-free process were often comparable or better than those from a traditional sacrificial-anode process. Examining a wide variety of substrates shows a correlation between known nucleophilic susceptibilities of carbon-halide bonds and selectivity loss in the absence of a Mg2+source. The carboxylate anion product was also discovered to mitigate cathodic passivation by insoluble carbonates produced as byproducts from concomitant CO2reduction to CO, although this protection can eventually become insufficient when sacrificial anodes are used. These results are a key step toward sustainable and practical carboxylation by providing an electrolyte design guideline to obviate the need for sacrificial anodes.
Photochemical Control of the Mechanical and Adhesive Properties of Crystalline Molecular Solids
Blelloch, Nicholas D.,Mitchell, Haydn T.,Greenburg, Louisa C.,Van Citters, Douglas W.,Mirica, Katherine A.
, p. 6143 - 6154 (2021/11/01)
This paper describes a systematic investigation of the mechanical and adhesive properties of four novel photoresponsive crystalline molecular solids. Each molecular solid comprises a benzyl, naphthyl, or adamantyl scaffold modified with a nitrobenzyl photolabile protecting group. Mechanical and adhesive testing, which recorded shear strengths in the range of 50-150 kPa, provide a direct measurement of the strength of the interfacial intermolecular interactions present within these materials. These interactions were visualized and rationalized using X-ray diffraction techniques and light microscopy. Disruption of interfacial interactions is facilitated by light-induced deprotection of the nitrobenzyl group. Depending on the strategic selection of adhesive, UV irradiation may result in up to a 4-fold increase or in a complete elimination in the observed adhesive strength. The change in adhesion exhibited by each material is determined, in part, by the extent of the solid-state photoconversion, which ranges from 5% to 26%, as well as the relative strength of the interfacial interactions present before and after irradiation. This research demonstrates the ability to tailor the emergent macroscopic mechanical properties of crystalline materials through strategic molecular design.
An Anionic, Chelating C(sp3)/NHC ligand from the Combination of an N-heterobicyclic Carbene and Barbituric Heterocycle
Benaissa, Idir,Gajda, Katarzyna,Vendier, Laure,Lugan, No?l,Kajetanowicz, Anna,Grela, Karol,Michelet, Véronique,César, Vincent,Bastin, Stéphanie
supporting information, p. 3223 - 3234 (2021/09/30)
The coordination chemistry of the anionic NHC1-based on an imidazo[1,5-a]pyridin-3-ylidene (IPy) platform substituted at the C5 position by an anionic barbituric heterocycle was studied with d6(Ru(II), Mn(I)) and d8(Pd(II), Rh(I), Ir(I), Au(III)) transition-metal centers. While the anionic barbituric heterocycle is planar in the zwitterionic NHC precursor 1·H, NMR spectroscopic analyses supplemented by X-ray diffraction studies evidenced the chelating behavior of ligand 1-through the carbenic and the malonic carbon atoms in all of the complexes, resulting from a deformation of the lateral barbituric heterocycle. The complexes were obtained by reaction of the free carbene with the appropriate metal precursor, except for the Au(III) complex 10, which was obtained by oxidation of the antecedent gold(I) complex [AuCl(1)]?with PhICl2as an external oxidant. During the course of the process, the kinetic gold(I) intermediate 9 resulting from the oxidation of the malonic carbon of the barbituric moiety was isolated upon crystallization from the reaction mixture. The νCOstretching frequencies recorded for complex [Rh(1)(CO)2] (5) demonstrated the strong donating character of the malonate-C(sp3)/NHC ligand 1-. The ruthenium complex [Ru(1)Cl(p-cymene)] (11) was implemented as a precatalyst in the dehydrogenative synthesis of carboxylic acid derivatives from primary alcohols and exhibited high activities at low catalyst loadings (25-250 ppm) and a large tolerance toward functional groups.
Hydrolysis of amides to carboxylic acids catalyzed by Nb2O5
Siddiki,Rashed, Md. Nurnobi,Touchy, Abeda Sultana,Jamil, Md. A. R.,Jing, Yuan,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-Ichi
, p. 1949 - 1960 (2021/03/26)
Hydrolysis of amides to carboxylic acids is an industrially important reaction but is challenging due to the difficulty of cleaving the resonance stabilized amidic C-N bond. Twenty-three heterogeneous and homogenous catalysts were examined in the hydrolysis of acetamide. Results showed that Nb2O5was the most effective heterogeneous catalyst with the greatest yield of acetic acid. A series of Nb2O5catalysts calcined at various temperatures were characterized and tested in the hydrolysis of acetamide to determine the effects of crystal phase and surface properties of Nb2O5on catalytic performance. The high catalytic performance observed was attributed mainly to the facile activation of the carbonyl bond by Lewis acid sites that function even in the presence of basic inhibitors (NH3and H2O). The catalytic studies showed the synthetic advantages of the present method, such as simple operation, catalyst recyclability, additive free, solvent free, and wide substrate scope (>40 examples; up to 95% isolated yield).
Oxidation of Primary Alcohols and Aldehydes to Carboxylic Acids via Hydrogen Atom Transfer
Tan, Wen-Yun,Lu, Yi,Zhao, Jing-Feng,Chen, Wen,Zhang, Hongbin
supporting information, p. 6648 - 6653 (2021/09/08)
The oxidation of primary alcohols and aldehydes to the corresponding carboxylic acids is a fundamental reaction in organic synthesis. In this paper, we report a new chemoselective process for the oxidation of primary alcohols and aldehydes. This metal-free reaction features a new oxidant, an easy to handle procedure, high isolated yields, and good to excellent functional group tolerance even in the presence of vulnerable secondary alcohols and tert-butanesulfinamides.
ADAMANTANYL-SUBSTITUTED BENZAMIDE COMPOUNDS AND THEIR USE AS P2X7 RECEPTOR ANTAGONISTS
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Page/Page column 20-22, (2020/03/15)
The present invention relates to adamantanyl-substituted benzamide compounds and their use as antagonists of the P2X7 purinoreceptor. The invention further relates to methods for the treatment of disease and conditions associated with the P2X7 purinoreceptor.
A recyclable, metal-free mechanochemical approach for the oxidation of alcohols to carboxylic acids
Carr, Preston,Denlinger, Kendra Leahy,Mack, James,Waddell, Daniel C.
, (2020/01/28)
The oxidation of primary alcohols under mechanochemical conditions in a Spex8000M Mixer/Mill was investigated. To facilitate ease of separation and recyclability, a polystyrene-bound version of a TEMPO catalyst was employed. When paired with Oxone in a stainless-steel vial with a stainless-steel ball, several primary alcohols were successfully oxidized to the corresponding carboxylic acids. The product was isolated using gravity filtration, which also allowed for the polystyrene-bound TEMPO catalyst to be recovered and reused in subsequent oxidation reactions. Furthermore, it was demonstrated that the size and steric hindrance of the primary alcohol does not hinder the rate of the reaction. Finally, the aldehyde was selectively obtained from a primary alcohol under ball milling conditions by using a combination of non-supported TEMPO with a copper vial and copper ball.
