6056-23-1Relevant academic research and scientific papers
Coupling of Reformatsky Reagents with Aryl Chlorides Enabled by Ylide-Functionalized Phosphine Ligands
Hu, Zhiyong,Wei, Xiao-Jing,Handelmann, Jens,Seitz, Ann-Katrin,Rodstein, Ilja,Gessner, Viktoria H.,Goo?en, Lukas J.
supporting information, p. 6778 - 6783 (2021/02/01)
The coupling of aryl chlorides with Reformatsky reagents is a desirable strategy for the construction of α-aryl esters but has so far been substantially limited in the substrate scope due to many challenges posed by various possible side reactions. This limitation has now been overcome by the tailoring of ylide-functionalized phosphines to fit the requirements of Negishi couplings. Record-setting activities were achieved in palladium-catalyzed arylations of organozinc reagents with aryl electrophiles using a cyclohexyl-YPhos ligand bearing an ortho-tolyl-substituent in the backbone. This highly electron-rich, bulky ligand enables the use of aryl chlorides in room temperature couplings of Reformatsky reagents. The reaction scope covers diversely functionalized arylacetic and arylpropionic acid derivatives. Aryl bromides and chlorides can be converted selectively over triflate electrophiles, which permits consecutive coupling strategies.
Synthetic method of benzofuranone
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Paragraph 0057; 0059; 0062, (2020/06/16)
The invention provides a synthetic method of benzofuranone. According to the method, o-cresol which is relatively easy to obtain is used as an initial raw material, and the target product benzofuranone is prepared through four-step reaction; and the whole preparation process is mild in condition, high in yield, easy to operate, small in environmental pollution and suitable for large-scale industrial production.
Thermal Stability and Explosive Hazard Assessment of Diazo Compounds and Diazo Transfer Reagents
Green, Sebastian P.,Wheelhouse, Katherine M.,Payne, Andrew D.,Hallett, Jason P.,Miller, Philip W.,Bull, James A.
supporting information, p. 67 - 84 (2020/01/31)
Despite their wide use in academia as metal-carbene precursors, diazo compounds are often avoided in industry owing to concerns over their instability, exothermic decomposition, and potential explosive behavior. The stability of sulfonyl azides and other diazo transfer reagents is relatively well understood, but there is little reliable data available for diazo compounds. This work first collates available sensitivity and thermal analysis data for diazo transfer reagents and diazo compounds to act as an accessible reference resource. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and accelerating rate calorimetry (ARC) data for the model donor/acceptor diazo compound ethyl (phenyl)diazoacetate are presented. We also present a rigorous DSC dataset with 43 other diazo compounds, enabling direct comparison to other energetic materials to provide a clear reference work to the academic and industrial chemistry communities. Interestingly, there is a wide range of onset temperatures (Tonset) for this series of compounds, which varied between 75 and 160 °C. The thermal stability variation depends on the electronic effect of substituents and the amount of charge delocalization. A statistical model is demonstrated to predict the thermal stability of differently substituted phenyl diazoacetates. A maximum recommended process temperature (TD24) to avoid decomposition is estimated for selected diazo compounds. The average enthalpy of decomposition (?"HD) for diazo compounds without other energetic functional groups is-102 kJ mol-1. Several diazo transfer reagents are analyzed using the same DSC protocol and found to have higher thermal stability, which is in general agreement with the reported values. For sulfonyl azide reagents, an average ?"HD of-201 kJ mol-1 is observed. High-quality thermal data from ARC experiments shows the initiation of decomposition for ethyl (phenyl)diazoacetate to be 60 °C, compared to that of 100 °C for the common diazo transfer reagent p-acetamidobenzenesulfonyl azide (p-ABSA). The Yoshida correlation is applied to DSC data for each diazo compound to provide an indication of both their impact sensitivity (IS) and explosivity. As a neat substance, none of the diazo compounds tested are predicted to be explosive, but many (particularly donor/acceptor diazo compounds) are predicted to be impact-sensitive. It is therefore recommended that manipulation, agitation, and other processing of neat diazo compounds are conducted with due care to avoid impacts, particularly in large quantities. The full dataset is presented to inform chemists of the nature and magnitude of hazards when using diazo compounds and diazo transfer reagents. Given the demonstrated potential for rapid heat generation and gas evolution, adequate temperature control and cautious addition of reagents that begin a reaction are strongly recommended when conducting reactions with diazo compounds.
Preparation of Organic Nitrates from Aryldiazoacetates and Fe(NO3)3·9H2O
Thurow, Samuel,Fernandes, Alessandra A. G.,Quevedo-Acosta, Yovanny,De Oliveira, Matheus F.,De Oliveira, Marcelo G.,Jurberg, Igor D.
supporting information, p. 6909 - 6913 (2019/09/12)
A thermal protocol is reported for the formal insertion of nitric acid into aryldiazoacetates using Fe(NO3)3·9H2O. This strategy is mild and high yielding and allows the preparation of a large variety of members of an unprecedented family of organic nitrates. The nitrate group can be also readily transformed into other functional groups and heterocyclic moieties and can possibly allow new biological explorations of untapped potential associated with their NO-releasing ability.
ARTIFICIAL METALLOENZYMES CONTAINING NOBLE METAL-PORPHYRINS
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Paragraph 0240, (2018/11/21)
The present invention is drawn to artificial metalloenzymes for use in cyclopropanation reactions, amination and C—H insertion.
Mechanistic studies on gold-catalyzed direct arene c-h bond functionalization by carbene insertion: The coinage-metal effect
Fructos, Manuel R.,Besora, Maria,Braga, Ataualpa A. C,Díaz-Requejo, M. Mar,Maseras, Feliu,Perez, Pedro J.
, p. 172 - 179 (2017/04/04)
The catalytic functionalization of the Csp2-H bond of benzene by means of the insertion of the CHCO2Et group from ethyl diazoacetate (N2= CHCO2Et) has been studied with the series of coinage-metal complexes IPrMCl (IPr = 1,3-bis- (diisopropylphenyl)imidazol-2-ylidene) and NaBArF 4 (BArF 4 = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate). For Cu and Ag, these examples constitute the first use of such metals toward this transformation, which also provides ethyl cyclohepta-2,4,6-trienecarboxylate as a byproduct from the so-called Buchner reaction. In the case of methyl-substituted benzenes, the reaction exclusively proceeds onto the aromatic ring, the Csp3-H bond remaining unreacted. A significant coinage-metal effect has been observed, since the gold catalyst favors the formation of the insertion product into the Csp2-H bond whereas copper and silver preferentially induce the formation of the cycloheptatriene derivative. Experimental studies and theoretical calculations have explained the observed selectivity in terms of the formation of a common Wheland intermediate, resembling an electrophilic aromatic substitution, from which the reaction pathway evolves into two separate routes to each product.
Chlorotrimethylsilane and Sodium Iodide: A Useful Combination for the Regioselective Deoxygenation of Arylalkyl-α-Diketones
Yuan, Ling-Zhi,Zhao, Guangkuan,Hamze, Abdallah,Alami, Mouad,Provot, Olivier
, p. 2682 - 2691 (2017/08/16)
An efficient regioselective deoxygenation of arylalkyl-1,2-diketones by the couple trimethylsilylchloride/sodium iodide has been reported. In all cases, the deoxygenation takes place on the carbonyl group (Cα=O) proximal to the aromatic ring in methylene chloride at room temperature in good yields, furnishing a series of variously functionalized alkylbenzylketones. A large range of functional groups were well tolerated on the ortho-, meta- and para-positions by this mild process regardless of their electronic effects, demonstrating the general character of the present methodology. The trimethylsilylchloride/sodium iodide reducing process was also successfully applied to reduce α-ketoacid and α-ketoester substrates. (Figure presented.).
Iron and manganese catalysts for the selective functionalization of arene C(sp2)-H bonds by carbene insertion
Conde, Ana,Sabenya, Gerard,Rodríguez, Mònica,Postils, Verònica,Luis, Josep M.,Díaz-Requejo, M. Mar,Costas, Miquel,Pérez, Pedro J.
supporting information, p. 6530 - 6534 (2016/06/01)
The first examples of the direct functionalization of non-activated aryl sp2 C-H bonds with ethyl diazoacetate (N2CHCO2Et) catalyzed by Mn- or Fe-based complexes in a completely selective manner are reported, with no formation of the frequently observed cycloheptatriene derivatives through competing Buchner reaction. The best catalysts are FeII or MnII complexes bearing the tetradentate pytacn ligand (pytacn= 1-(2-pyridylmethyl)-4,7-dimethyl-1,4,7-triazacyclononane). When using alkylbenzenes, the alkylic C(sp3)-H bonds of the substituents remained unmodified, thus the reaction being also selective toward functionalization of sp2 C-H bonds. Exclusive catalysis: Iron- and-manganese-based catalysts selectively functionalize the C(sp2)-H bonds of benzene or alkylbenzenes through the formal insertion of the CHCO2Et group from N2CHCO2Et (see scheme). When using alkylbenzenes, the alkylic C(sp3)-H bonds of the substituents remain unmodified.
Novel synthesis of benzofuran- and indol-2-yl-methanamine derivatives
Schlosser, Joachim,Johannes, Eugen,Zindler, Melanie,Lemmerhirt, Jan,Sommer, Benjamin,Schütt, Martin,Peifer, Christian
supporting information, p. 89 - 94 (2015/02/02)
We report on a novel synthesis towards benzofuran-2-yl-methanamine and indol-2-yl-methanamine derivatives by using ortho-methoxy and ortho-nitro substituted phenylacetic acids as starting material, respectively. For each compound series, a key intermediate bearing the oxazole-4-carboxylic acid methylester moiety was produced. Refluxing the ortho-methoxy series in HBr/HAc produced the desired benzofuran-2-yl-methanamines. Accordingly, for the synthesis of indoles the nitro-group was first reduced and refluxing these intermediates in HCl gave the corresponding indol-2-yl-methanamines. The method worked well with electron donating substituents. Limitations regarding electron withdrawing substituents are discussed. This straightforward synthetic procedure can be a useful approach to generate a variety of substituted benzofuran-2-yl-methanamine and indol-2-yl-methanamine compounds by starting from readily available phenylacetic acid derivatives.
Alcohol assisted C-C bond breaking: Copper-catalyzed deacetylative α-arylation of β-keto esters and amides
Ke, Jie,He, Chuan,Liu, Huiying,Xu, Huan,Lei, Aiwen
supporting information, p. 6767 - 6769 (2013/07/26)
A method of alcohol-assisted copper-catalyzed highly selective deacetylative α-arylation of β-keto esters and amides has been demonstrated, which illustrated an efficient example of achieving α-aryl esters and amides. From the synthetic point of view, this arylation protocol is general and practical, representing a simple way to produce α-arylated carbonyl compounds from basic starting materials at low cost.
