2741-16-4Relevant articles and documents
Radical Anion Promoted Chemoselective Cleavage of Csp2-S Bond Enables Formal Cross-Coupling of Aryl Methyl Sulfones with Alcohols
Bai, Jixiang,Wang, Tianxin,Dai, Botao,Liu, Qingchao,Yu, Peiyuan,Jia, Tiezheng
supporting information, p. 5761 - 5765 (2021/08/16)
A novel formal cross-coupling of aryl methyl sulfones and alcohols affording alkyl aryl ethers via an SRN1 pathway is developed. Two marketed antitubercular drugs were efficiently prepared employing this approach as the key step. A dimsyl-anion initiated radical chain process was revealed as the major pathway. DFT calculations indicate that the formation of a radical anion via nucleophilic addition of alkoxide to the aryl radical is the key step in determining the observed chemoselectivity.
Removal of Alkyl Sulfonates Using DABCO
Corazzata, Kaitlyn,Langston, Alexander,Lee, Elaine C.,Mo, Shunyan,Rose, Peter J.,Snodgrass, Joseph
supporting information, (2021/11/30)
During the route development of a midstage clinical candidate, we were challenged with a presence of alkyl sulfonates, which were identified as potential genotoxic impurities in our active pharmaceutical ingredient (API). As a result, we initiated a development effort to identify a method to remove the alkyl sulfonates that would be amenable for scale-up. Herein, we report our effort toward the development of a general approach using DABCO (1,4-diazabicyclo[2.2.2]octane) to remove alkyl sulfonates that is both efficient and convenient from the bench to scale-up.
Synthesis of Sulfonimidamides from Sulfenamides via an Alkoxy-amino-λ6-sulfanenitrile Intermediate
Briggs, Edward L.,Tota, Arianna,Colella, Marco,Degennaro, Leonardo,Luisi, Renzo,Bull, James A.
supporting information, p. 14303 - 14310 (2019/09/06)
Sulfonimidamides are intriguing new motifs for medicinal and agrochemistry, and provide attractive bioisosteres for sulfonamides. However, there remain few operationally simple methods for their preparation. Here, the synthesis of NH-sulfonimidamides is achieved directly from sulfenamides, themselves readily formed in one step from amines and disulfides. A highly chemoselective and one-pot NH and O transfer is developed, mediated by PhIO in iPrOH, using ammonium carbamate as the NH source, and in the presence of 1 equivalent of acetic acid. A wide range of functional groups are tolerated under the developed reaction conditions, which also enables the functionalization of the antidepressants desipramine and fluoxetine and the preparation of an aza analogue of the drug probenecid. The reaction is shown to proceed via different and concurrent mechanistic pathways, including the formation of novel S≡N sulfanenitrile species as intermediates. Several alkoxy-amino-λ6-sulfanenitriles are prepared with different alcohols, and shown to be alkylating agents to a range of nucleophiles.
Synthesis and catalytic performance of HMCM-49/MCM-41 composite molecular sieve for alkylation of phenol with isopropanol
Wei, Liguo,Wang, Dong,Dong, Yongli,Song, Weina,Liu, Xiaoxu,Song, Kunyao
, p. 2061 - 2066 (2017/01/28)
HMCM-49/MCM-41 composite molecular sieve was synthesized with hydrothermal method. The physicochemical properties of the composite were characterized by using XRD, FT-IR, SEM, N2 isothermal adsorption-desorption and NH3-TPD. Results of different characterizations indicated that the synthesized composite molecular sieve possessed the characteristics of both HMCM-49 and MCM-41. XRD and N2 isothermal adsorption-desorption revealed that it has both micropores and mesopores, a larger surface area than that of HMCM-49, NH3-TPD and pyridine adsorbed FT-IR revealed that the strong acidic sites that caused side reaction in HMCM-49 are deactivated in the composite molecular sieve of HMCM-49/MCM-41. When applied to the alkylation of phenol with isopropanol, the HMCM-49/MCM-41 composite molecular sieve exhibit an enhanced catalytic performance with significant enhancement in p-isopropylphenol and o-isopropylphenol selectivity, which can be ascribed to the composite characteristics of HMCM-49 and MCM-41. This kind of material will has widely industrial application in preparation of alkyl-phenol.
Conversion of Cyclohexanones to Alkyl Aryl Ethers by Using a Pd/C–Ethylene System
El-Deeb, Ibrahim Yussif,Tian, Miaomiao,Funakoshi, Tatsuya,Matsubara, Ryosuke,Hayashi, Masahiko
, p. 409 - 413 (2017/01/24)
The conversion of cyclohexanone and substituted cyclohexanones into alkyl aryl ethers by using a Pd/C–ethylene system is discussed, with ethylene functioning as a hydrogen acceptor. The ether products are easily transformed into the corresponding phenols by treatment with BBr3. The direct conversion of cyclohexenone into phenol in the presence of a catalytic amount of Pd/C under an ethylene atmosphere is also described.
Catalytic transfer hydrogenation/hydrogenolysis of guaiacol to cyclohexane over bimetallic RuRe/C catalysts
Kim, Mookyung,Ha, Jeong-Myeong,Lee, Kwan-Young,Jae, Jungho
, p. 113 - 118 (2016/08/25)
The hydrodeoxygenation of lignin monomer guaiacol via catalytic transfer hydrogenation was studied with 2-propanol as a hydrogen donor and Ru-based catalysts. Guaiacol was mainly converted into a partially deoxygenated product, cyclohexanol (>?70% selectivity), over Ru/C catalysts with the hydrogen produced in-situ from 2-propanol. An addition of Re to Ru/C catalysts significantly enhanced the rate of C—O hydrogenolysis, resulting in the complete deoxygenation to cyclohexane (~?60% selectivity). The remarkable deoxygenation ability of the bimetallic RuRe/C catalyst is attributed to its bifunctional characteristic, by which Ru catalyzes the hydrogenation-hydrogenolysis of guaiacol and Re provides acid sites to promote cyclohexane production via hydrogenolysis.
Intermolecular C–O Coupling Using Hemicucurbituril Supported Ionic Liquid Phase Catalyst
Kurane, Rajanikant,Bansode, Prakash,Khanapure, Sharanabasappa,Kale, Dolly,Salunkhe, Rajashri,Rashinkar, Gajanan
, p. 2485 - 2494 (2016/11/25)
Abstract: Hemicucurbituril supported ionic liquid phase catalyst (HmCucSILP) has been synthesized by anchoring multilayer of ionic liquid ([Bmim]Cl) containing Pd(OAc)2 and X-phos on the surface of hemicucurbit[6]uril. The HmCucSILP was effectively employed in intermolecular C–O coupling of aryl halides with sodium alkoxides for the synthesis of alkyl aryl ethers. Graphical Abstract: [Figure not available: see fulltext.]
Air-stable palladium(0) phosphine sulfide catalysts for Ullmann-type C-N and C-O coupling reactions
Majumder, Arpi,Gupta, Ragini,Mandal, Mrinmay,Babu, Madhu,Chakraborty, Debashis
, p. 23 - 34 (2015/03/05)
This paper describes an efficient procedure for palladium(0)-catalyzed N-arylation and O-arylation of aryl halides by Ullmann-type cross coupling reaction under mild reaction conditions in a short reaction time. Two phosphine sulphide ligands and their corresponding Pd(0) complexes namely [Pd(p2S2)(dba)] and [Pd(pp3S4)(dba)], were synthesized, where p2S2 is 1,2-bis(diphenylphosphino)ethane disulfide, pp3S4 is tris[2-(diphenylphosphino)ethyl]phosphine tetrasulfide and dba is dibenzylideneacetone. Optimal reaction conditions were determined for the arylation reactions using iodobenzene and benzimidazole by varying temperature, solvent, base and catalyst loading. The cross coupling reactions were carried out taking iodobenzenes/bromobenzenes and a wide variety of substituted aryl amines/phenols/alcohols with different steric and electronic properties to afford the desired N-aryl amines/diaryl ethers/alkyl aryl ethers in good to excellent yield (70-94%).
The ortho-substituent effect on the Ag-Catalysed decarboxylation of benzoic acids
Grainger, Rachel,Cornella, Josep,Blakemore, David C.,Larrosa, Igor,Campanera, Josep M.
supporting information, p. 16680 - 16687 (2015/03/05)
A combined experimental and computational investigation on the Ag-catalysed decarboxylation of benzoic acids is reported herein. The present study demonstrates that a substituent at the ortho position exerts dual effects in the decarboxylation event. On one hand, ortho-substituted benzoic acids are inherently destabilised starting materials compared to their meta- And para-substituted counterparts. On the other hand, the presence of an ortho-electron-withdrawing group results in an additional stabilisation of the transition state. The combination of both effects results in an overall reduction of the activation energy barrier associated with the decarboxylation event. Furthermore, the Fujita- Nishioka linear free energy relationship model indicates that steric bulk of the substituent can also exert a negative effect by destabilising the transition state of decarboxylation.
Olefin hydroaryloxylation catalyzed by pincer-iridium complexes
Haibach, Michael C.,Guan, Changjian,Wang, David Y.,Li, Bo,Lease, Nicholas,Steffens, Andrew M.,Krogh-Jespersen, Karsten,Goldman, Alan S.
supporting information, p. 15062 - 15070 (2013/11/06)
Aryl alkyl ethers, which are widely used throughout the chemical industry, are typically produced via the Williamson ether synthesis. Olefin hydroaryloxylation potentially offers a much more atom-economical alternative. Known acidic catalysts for hydroaryloxylation, however, afford very poor selectivity. We report the organometallic-catalyzed intermolecular hydroaryloxylation of unactivated olefins by iridium "pincer" complexes. These catalysts do not operate via the hidden Br?nsted acid pathway common to previously developed transition-metal-based catalysts. The reaction is proposed to proceed via olefin insertion into an iridium-alkoxide bond, followed by rate-determining C-H reductive elimination to yield the ether product. The reaction is highly chemo- and regioselective and offers a new approach to the atom-economical synthesis of industrially important ethers and, potentially, a wide range of other oxygenates.
