- PRMTI Type methyltransferase inhibition active compound as well as preparation and application thereof
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The invention relates to a compound with PRMT I-type methyltransferase inhibition activity and preparation and application thereof, wherein the compound has the structure shown I. The compound of the formula I has a good inhibition effect on PRMT I-type m
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Paragraph 0014
(2021/11/03)
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- Synthesis, inhibition properties against xanthine oxidase and molecular docking studies of dimethyl N-benzyl-1H-1,2,3-triazole-4,5-dicarboxylate and (N-benzyl-1H-1,2,3-triazole-4,5-diyl)dimethanol derivatives
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This study focused on synthesis various dimethyl N-benzyl-1H-1,2,3-triazole-4,5-dicarboxylate and (N-benzyl-1H-1,2,3-triazole-4,5-diyl)dimethanol derivatives under the conditions of green chemistry without the use of solvent and catalysts. Their inhibition properties were also investigated on xanthine oxidase (XO) activity. All dimethanol and dicarboxylate derivatives exhibited significant inhibition activities with IC50 values ranging from 0.71 to 2.25 μM. Especially, (1-(3-bromobenzyl)-1H-1,2,3-triazole-4,5-diyl)dimethanol (5c) and dimethyl 1-(4-chlorobenzyl)-1H-1,2,3-triazole-4,5-dicarboxylate (6 g) compounds were found to be the most promising derivatives on the XO enzyme inhibition with IC50 values 0.71 and 0.73 μM, respectively. Moreover, the double docking procedure was to evaluate compound modes of inhibition and their interactions with the protein (XO) at atomic level. Surprisingly, the docking results showed a good correlation with IC50 [correlation coefficient (R2 = 0.7455)]. Also, the docking results exhibited that the 5c, 6f and 6 g have lowest docking scores ?4.790, ?4.755, and ?4.730, respectively. These data were in agreement with the IC50 values. These results give promising beginning stages to assist in the improvement of novel and powerful inhibitor against XO.
- Yagiz, Güler,Noma, Samir Abbas Ali,Altundas, Aliye,Al-khafaji, Khattab,Taskin-Tok, Tugba,Ates, Burhan
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- Synthesis, Docking, and Biological activities of novel Metacetamol embedded [1,2,3]-triazole derivatives
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ERα controls the breast tissue development and progression of breast cancer. In our search for novel compounds to target Estrogen Receptor Alpha Ligand-Binding Domain, we identified “N-(3-((1H-1,2,3-triazol-4-yl)methoxy)phenyl)acetamide” derivatives as lead compounds. The Docking studies indicated good docking score for Metacetamol derivatives when docked into the 1XP6. A series of metacetamol derivatives have been synthesized, characterized and evaluated for cytotoxicity, anti bacterial and anti oxidant activities. Among the tested twelve hybrid compounds, “7a, 7g, 7h and 7i” derivatives showed promising cytotoxicity with IC50 value of 50 value of 30 μM, whereas Compounds “7a, 7b, 7c, 7d, 7g, 7j, 7k and 7l” showed moderate anti bacterial activity with the MIC value of 300 μM.
- Battu, Satyanarayana,Joolakanti, Hima Bindhu,Kamepalli, Ramanjaneyulu,Miryala, Jeevanreddy
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- [1,3]-Claisen rearrangement via removable functional group mediated radical stabilization
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A thermal O-to-C [1,3]-rearrangement of α-hydroxy acid derived enol ethers was achieved under mild conditions. The 2-aminothiophenol protection of carboxylic acids facilitates formation of the [1,3] precursor and its thermal rearrangement via stabilization of a radical intermediate. Experimental and theoretical evidence for dissociative radical pair formation, its captodative stability via aminothiophenol, and a unique solvent effect are presented. The aminothiophenol was deprotected from rearrangement products as well as after derivatization to useful synthons.
- Alam, Md Nirshad,Dash, Soumya Ranjan,Mukherjee, Anirban,Pandole, Satish,Marelli, Udaya Kiran,Vanka, Kumar,Maity, Pradip
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supporting information
p. 890 - 895
(2021/02/01)
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- Photochemical benzylic bromination in continuous flow using BrCCl3 and its application to telescoped p-methoxybenzyl protection
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BrCCl3 represents a rarely used benzylic brominating reagent with complementary reactivity to other reagents. Its reactivity has been revisited in continuous flow, revealing compatibility with electron-rich aromatic substrates. This has brought about the development of a p-methoxybenzyl bromide generator for PMB protection, which was successfully demonstrated on a pharmaceutically relevant intermediate on 11 g scale, giving 91% yield and a PMB-Br space-time-yield of 1.27 kg L?1 h?1
- Otake, Yuma,Williams, Jason D.,Rincón, Juan A.,De Frutos, Oscar,Mateos, Carlos,Kappe, C. Oliver
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supporting information
p. 1384 - 1388
(2019/02/14)
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- Strategy for Overcoming Full Reversibility of Intermolecular Radical Addition to Aldehydes: Tandem C-H and C-O Bonds Cleaving Cyclization of (Phenoxymethyl)arenes with Carbonyls to Benzofurans
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An intermolecular addition of carbon radicals enabled by a cascade radical coupling strategy is developed. It includes an intermolecular alkyl radical addition to a carbonyl group followed by an intramolecular alkoxy radical addition to haloarenes and produces substituted benzofurans in high yields. The radical nature of this reaction is explored by radical trapping experiments and EPR analysis. The mechanism is investigated by KIE experiments and control experiments. This method could provide rapid and practical access to the key intermediate of TAM-16, a safe and potent antibacterial agent for treating tuberculosis, and, therefore, is of great importance for organic synthesis and the pharmaceutical industry.
- Zheng, Hong-Xing,Shan, Xiang-Huan,Qu, Jian-Ping,Kang, Yan-Biao
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p. 3310 - 3313
(2018/06/11)
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- Selective C-H halogenation over hydroxylation by non-heme iron(iv)-oxo
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Non-heme iron based halogenase enzymes promote selective halogenation of the sp3-C-H bond through iron(iv)-oxo-halide active species. During halogenation, competitive hydroxylation can be prevented completely in enzymatic systems. However, synthetic iron(iv)-oxo-halide intermediates often result in a mixture of halogenation and hydroxylation products. In this report, we have developed a new synthetic strategy by employing non-heme iron based complexes for selective sp3-C-H halogenation by overriding hydroxylation. A room temperature stable, iron(iv)-oxo complex, [Fe(2PyN2Q)(O)]2+ was directed for hydrogen atom abstraction (HAA) from aliphatic substrates and the iron(ii)-halide [FeII(2PyN2Q)(X)]+ (X, halogen) was exploited in conjunction to deliver the halogen atom to the ensuing carbon centered radical. Despite iron(iv)-oxo being an effective promoter of hydroxylation of aliphatic substrates, the perfect interplay of HAA and halogen atom transfer in this work leads to the halogenation product selectively by diverting the hydroxylation pathway. Experimental studies outline the mechanistic details of the iron(iv)-oxo mediated halogenation reactions. A kinetic isotope study between PhCH3 and C6D5CD3 showed a value of 13.5 that supports the initial HAA step as the RDS during halogenation. Successful implementation of this new strategy led to the establishment of a functional mimic of non-heme halogenase enzymes with an excellent selectivity for halogenation over hydroxylation. Detailed theoretical studies based on density functional methods reveal how the small difference in the ligand design leads to a large difference in the electronic structure of the [Fe(2PyN2Q)(O)]2+ species. Both experimental and computational studies suggest that the halide rebound process of the cage escaped radical with iron(iii)-halide is energetically favorable compared to iron(iii)-hydroxide and it brings in selective formation of halogenation products over hydroxylation.
- Rana, Sujoy,Biswas, Jyoti Prasad,Sen, Asmita,Clémancey, Martin,Blondin, Geneviève,Latour, Jean-Marc,Rajaraman, Gopalan,Maiti, Debabrata
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p. 7843 - 7858
(2018/10/31)
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- Synthesis of Novel Triazole-incorporated Isatin Derivatives as Antifungal, Antitubercular, and Antioxidant Agents and Molecular Docking Study
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A library of 1,2,3-triazoles efficiently prepared via click chemistry and evaluated for their antifungal, antitubercular, antioxidant, cytotoxicity, molecular docking and ADME prediction.
- Shaikh, Mubarak H.,Subhedar, Dnyaneshwar D.,Khan, Firoz A. Kalam,Sangshetti, Jaiprakash N.,Nawale, Laxman,Arkile, Manisha,Sarkar, Dhiman,Shingate, Bapurao B.
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p. 413 - 421
(2017/02/03)
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- Method for preparing benzyl bromide
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The invention provides a method for preparing benzyl bromide. The method comprises the following steps: by taking bromine released from a redox reaction between bromates and negative bromide ions in the presence of an acid as a bromine source in an organic solvent, carrying out a benzyl radical substitution reaction with a methylbenzene compound shown as a formula I under initiation of an initiator, thereby obtaining a corresponding benzyl bromide compound shown a formula II, wherein in the formula II, m represents the number of Br and is equal to 1 or 2; when m is equal to 1, the formula II shows a benzyl monobromo compound; and when m is equal to 2, the formula II shows a benzyl dibromo compound. The reaction is carried out in an organic solvent, the initiator is combined and used, the radical substitution reaction is high in selectivity and wide in substrate application range, the substituent group replacing methylbenzene may be an electron-withdrawing group or an electron-donating group and can give extremely high yield on strong electron-donating groups (such as methoxy group). Moreover, the method disclosed by the invention is also applicable to preparation of benzyl dibromo compounds, and the product yield is high.
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Paragraph 0040-0042
(2017/10/05)
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- Synthesis and bioactivity of novel triazole incorporated benzothiazinone derivatives as antitubercular and antioxidant agent
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In search of new active molecules against Mycobacterium tuberculosis (MTB) H37Ra and M. bovis BCG, a small focused library of benzothiazinone based 1,2,3-triazoles has been efficiently prepared via click chemistry approach. Several derivatives were found to be promising inhibitors of MTB and M. bovis BCG characterized by lower MIC values (27.34-29.37 μg/mL). Among all the synthesized compounds, 6c and 6e is the most active compound against MTB and M. bovis BCG. The compounds were further tested for anti-proliferative activity against HeLa, A549 and A431 cell lines using MTT assay and showed no significant cytotoxic activity at the maximum concentration evaluated. Further, the synthesized compounds were found to have potential antioxidant activity with IC50 range = 14.14-47.11 μg/mL. Furthermore, to rationalize the observed biological activity data, the molecular docking study also been carried out against a potential target MTB DprE1, which revealed a significant correlation between the binding score and biological activity for these compounds. The results of the in vitro and in silico study suggest that the triazole incorporated benzothiazinone may possess the ideal structural requirements for further development of novel therapeutic agents.
- Shaikh, Mubarak H.,Subhedar, Dnyaneshwar D.,Arkile, Manisha,Khedkar, Vijay M.,Jadhav, Nandadeep,Sarkar, Dhiman,Shingate, Bapurao B.
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p. 561 - 569
(2016/01/09)
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- Discovery and structural optimization of 4-(4-(benzyloxy)phenyl)-3,4-dihydropyrimidin-2(1H)-ones as RORc inverse agonists
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Aim: Retinoic acid receptor-related orphan nuclear receptors (RORs) are orphan nuclear receptors that show constitutive activity in the absence of ligands. Among 3 subtypes of RORs, RORc is a promising therapeutic target for the treatment of Th17-mediated autoimmune diseases. Here, we report novel RORc inverse agonists discovered through structure-based drug design. Methods: Based on the structure of compound 8, a previously described agonist of RORa, a series of 4-(4-(benzyloxy)phenyl)-3,4-dihydropyrimidin-2(1H)-one derivatives were designed and synthesized. The interaction between the compounds and RORc was detected at molecular level using AlphaScreen assay. The compounds were further examined in 293T cells transfected with RORc and luciferase reporter gene. Thermal stability shift assay was used to evaluate the effects of the compounds on protein stability. Results: A total of 27 derivatives were designed and synthesized. Among them, the compound 22b was identified as the most potent RORc inverse agonist. Its IC50 values were 2.39 μmol/L in AlphaScreen assay, and 0.82 μmol/L in inhibition of the cell-based luciferase reporter activity. Furthermore, the compound 22b displayed a 120-fold selectivity for RORc over other nuclear receptors. Moreover, a molecular docking study showed that the structure-activity relationship was consistent with the binding mode of compound 22b in RORc. Conclusion: 4-(4-(Benzyloxy)phenyl)-3,4-dihydropyrimidin-2(1H)-one derivatives are promising candidates for the treatment of Th17-mediated autoimmune diseases, such as rheumatoid arthritis, psoriasis, and multiple sclerosis.
- Wu, Xi-Shan,Wang, Rui,Xing, Yan-Li,Xue, Xiao-Qian,Zhang, Yan,Lu, Yong-Zhi,Song, Yu,Luo, Xiao-Yu,Wu, Chun,Zhou, Yu-Lai,Jiang, Jian-Qin,Xu, Yong
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p. 1516 - 1524
(2016/11/11)
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- 1,2,3-Triazole incorporated coumarin derivatives as potential antifungal and antioxidant agents
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A series of novel ethyl-7-((1-(benzyl)-1H-1,2,3-triazol-4-yl)methoxy)-2-oxo-2H-chromene-3-carboxylates 8a-h as potential antifungal agents were synthesized via click chemistry. The antifungal activity was evaluated against five human pathogenic fungal strains, such as Candida albicans, Fusarium oxysporum, Aspergillus flavus, Aspergillus niger and Cryptococcus neoformans. Compound 8c, 8d, 8e and 8h were found to be equipotent against C. albicans when compared with miconazole and compound 8f was found to be two-fold more active compared with miconazole and equipotent to fluconazole against C. albicans. The coumarin-based triazole derivatives were also evaluated for antioxidant activity and compound 8a was found to be potent antioxidant when compared with standard drug. Furthermore, molecular docking study of the newly synthesized compounds was performed and results showed good binding mode in the active site of fungal C. albicans enzyme P450 cytochrome lanosterol 14α-demethylase. Moreover, the synthesized compounds were also analyzed for ADME properties and showed potential to build up as good oral drug candidates.
- Shaikh, Mubarak H.,Subhedar, Dnyaneshwar D.,Khan, Firoz A. Kalam,Sangshetti, Jaiprakash N.,Shingate, Bapurao B.
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p. 295 - 301
(2018/03/22)
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- An efficient and selective method for the iodination and bromination of alcohols under mild conditions
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A straightforward and effective procedure for the conversion of a variety of alcohols into the corresponding alkyl iodides and bromides is described using KX/P2O5 (X = I, Br). The reactions were easily carried out in acetonitrile under mild conditions. Using this method, the selective conversion of benzylic alcohols in the presence of aliphatic alcohols was achieved.
- Khazdooz, Leila,Zarei, Amin,Aghaei, Hamidreza,Azizi, Ghobad,Gheisari, Mohammad Mehdi
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p. 168 - 171
(2015/12/30)
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- Uranyl Schiff base complexes as new heterogeneous catalysts for halogen exchange reactions between alkyl halides and elemental halogens
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Mild and effective procedure for the halogen exchange reaction of alkyl halides with elemental iodine and bromine catalyzed with uranyl Schiff base complexes in various aprotic solvents was developed. Corresponding alkyl bromides and iodides were obtained with high yields within 20—70 min. The structures of the target products were confirmed by physical and spectroscopic data.
- Naeimi,Nazifi
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p. 1814 - 1818
(2016/05/11)
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- Clay-Supported Cu(II) Catalyst: An Efficient, Heterogeneous, and Recyclable Catalyst for Synthesis of 1,4-Disubstituted 1,2,3-Triazoles from Alloxan-Derived Terminal Alkyne and Substituted Azides Using Click Chemistry
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A novel series of alloxan-derived 1,4-disubstituted 1,2,3-triazoles was synthesized in excellent yields under catalytic conditions using a click reaction strategy through 1,3-dipolar cycloaddition. Their structures have been ascertained on the basis of spectroanalytical and elemental analysis data. Synthesis of hybrid compounds with varying substitutions in the triazole ring was achieved by reaction between alloxan-derived terminal alkyne and a pertinent azide derivative in the presence of clay-Cu(II) as the catalyst in methanolic medium. Also, comparative evaluation of various catalytic systems [viz., CuI, CuSO4, CuI-zeolite, K10Ti, and clay-Cu(II)] was investigated. Of these catalytic systems, clay-Cu(II) was observed to be the best. The catalyst was recyclable for several runs without showing significant loss in its activity. The good selectivity, cost-efficiency, short reaction time, milder reaction conditions, and simple workup procedure are the added salient features of this synthetic protocol.
- Dubey, Nitin,Sharma, Pratibha,Kumar, Ashok
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p. 2608 - 2626
(2015/11/28)
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- A scalable procedure for light-induced benzylic brominations in continuous flow
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A continuous-flow protocol for the bromination of benzylic compounds with N-bromosuccinimide (NBS) is presented. The radical reactions were activated with a readily available household compact fluorescent lamp (CFL) using a simple flow reactor design based on transparent fluorinated ethylene polymer (FEP) tubing. All of the reactions were carried out using acetonitrile as the solvent, thus avoiding hazardous chlorinated solvents such as CCl4. For each substrate, only 1.05 equiv of NBS was necessary to fully transform the benzylic starting material into the corresponding bromide. The general character of the procedure was demonstrated by brominating a diverse set of 19 substrates containing different functional groups. Good to excellent isolated yields were obtained in all cases. The novel flow protocol can be readily scaled to multigram quantities by operating the reactor for longer time periods (throughput 30 mmol h-1), which is not easily possible in batch photochemical reactors. The bromination protocol can also be performed with equal efficiency in a larger flow reactor utilizing a more powerful lamp. For the bromination of phenylacetone as a model, a productivity of 180 mmol h -1 for the desired bromide was achieved.
- Cantillo, David,De Frutos, Oscar,Rincon, Juan A.,Mateos, Carlos,Oliver Kappe
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supporting information
p. 223 - 229
(2014/01/17)
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- Synthesis of 2,4-unsubstituted quinoline-3-carboxylic acid ethyl esters from arylmethyl azides via a domino process
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A convenient synthesis of 2,4-unsubstituted quinoline-3-carboxylic acid ethyl esters via a domino process is described. The synthesis employs arylmethyl azides as the precursor which undergoes an acid-promoted rearrangement to give an N-aryl iminium ion. Following the addition with ethyl 3-ethoxyacrylate, intramolecular electrophilic aromatic substitution, elimination and subsequent oxidation, the quinoline products were obtained in moderate to excellent yields.
- Tummatorn, Jumreang,Thongsornkleeb, Charnsak,Ruchirawat, Somsak,Gettongsong, Tanita
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supporting information
p. 1463 - 1467
(2013/05/08)
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- Polyvinylpyrrolidone-bromine complex: An efficient polymeric reagent for selective preparation of benzyl bromides in the presence of hexamethyldisilane
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Benzylic bromides were conveniently obtained in high yields via the reaction of the corresponding alcohols with crosslinked polyvinylpyrrolidone- bromine complex (PVPP-Br2)/hexamethyldisilane in chloroform at reflux condition. Selective conversion of benzyl alcohol to benzyl bromide in the presence of primary aliphatic alcohols, e.g. 2-phenylethanol was also achieved.
- Mokhtary, Masoud,Lakouraj, Moslem M.
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p. 305 - 309
(2012/10/29)
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- Atropoisomeric (P,N) ligands for the highly enantioselective Pd-catalyzed intramolecular asymmetric α-arylation of α-branched aldehydes
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Three-in-one: A short synthetic route readily gives access to a new class of chiral (P,N) ligands characterized by three distinct elements of chirality. These ligands are highly enantioselective in the challenging Pd-catalyzed intramolecular asymmetric α-
- Nareddy, Pradeep,Mantilli, Luca,Guenee, Laure,Mazet, Clement
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supporting information; scheme or table
p. 3826 - 3831
(2012/06/01)
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- Palladium-catalyzed intramolecular decarboxylative coupling of arene carboxylic acids/esters with aryl bromides
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Give me a ring? An efficient approach has been developed for the intramolecular decarboxylative coupling of arene carboxylic acids/esters with aryl bromides catalyzed by palladium (see scheme). From a synthetic viewpoint, this method is highly attractive because the catalyst loading is low, the optimized reaction conditions are mild, and the substrate scope is broad. Copyright
- Shen, Zengming,Ni, Zhenjie,Mo, Song,Wang, Jing,Zhu, Yamin
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supporting information; experimental part
p. 4859 - 4865
(2012/06/04)
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- N-Halosuccinimide/SiCl4 as general, mild and efficient systems for the α-monohalogenation of carbonyl compounds and for benzylic halogenation
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Combinations of N-halosuccinimide and tetrachlorosilane in acetonitrile were found to be efficient systems for the selective α-monohalogenation of carbonyl compounds as well as for benzylic halogenation under mild conditions.
- Salama, Tarek A.,Novák, Zoltán
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experimental part
p. 4026 - 4029
(2011/08/09)
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- Microwave-promoted, one-pot conversion of alkoxymethylated protected alcohols into their corresponding nitriles, bromides, and iodides using [bmim][InCl4] as a green catalyst
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The Lewis acid room temperature ionic liquid, [bmim][InCl4], was found to be an efficient and green catalyst for the highly chemoselective and one-pot conversion of MOM- or EOM-ethers into their corresponding nitriles, bromides, and iodides under microwave irradiation. The procedures are simple, rapid, and high yielding. The catalyst exhibited a remarkable reactivity and is reusable.
- Mirjafari, Arsalan,Mohammadpoor-Baltork, Iraj,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Khosropour, Ahmad Reza
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supporting information; experimental part
p. 3274 - 3276
(2010/07/18)
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- Benzylic bromination of toluene derivatives with boron tribromide
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A facile method for the benzylic bromination of toluene derivatives was developed. Various substituted toluenes were brominated with boron tribromide as bromine source in carbon tetrachloride at room temperature, affording their corresponding benzyl bromides in good yields.
- Chen, Hongbiao,Shen, Litao,Lin, Yuanbin
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experimental part
p. 998 - 1003
(2010/05/18)
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- A simple and regioselective α-bromination of alkyl aromatic compounds by two-phase electrolysis
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Electrochemical bromination of toluene and substituted toluenes by two-phase electrolysis yields the corresponding α-brominated products. The reaction has been carried out in a single compartment cell with platinum electrodes at 0°C in chloroform using an aqueous sodium bromide solution (60%) containing a catalytic amount of HBr. Two-phase electrolysis results in high yields (60-95%) of monobromo compounds with very high regioselectivity (>95%).
- Raju,Kulangiappar,Anbu Kulandainathan,Muthukumaran
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p. 7047 - 7050
(2007/10/03)
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- De novo design and synthesis of HIV-1 integrase inhibitors
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Existing AIDS therapies are out of reach for most HIV-infected people in developing countries and, where available, they are limited by their toxicity and their cost. New anti-HIV agents are needed urgently to combat emerging viral resistance and reduce the side effects associated with currently available drugs. Toward this end, LeapFrog, a de novo drug design program was used to design novel, potent, and selective inhibitors of HIV-1 integrase. The designed compounds were synthesized and tested for in vitro inhibition of HIV-1 integrase. Out of the 25 compounds that were designed, and synthesized, four molecules (compounds 23, 26, 43, and 59) showed moderate to low inhibition of HIV-1 integrase for 3′-processing and 3′- strand transfer activities. Nonetheless, these compounds possess structural features not seen in known HIV-1 integrase inhibitors and thus can serve as excellent leads for further optimization of anti-HIV-1 integrase activity.
- Makhija, Mahindra T.,Kasliwal, Rajesh T.,Kulkarni, Vithal M.,Neamati, Nouri
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p. 2317 - 2333
(2007/10/03)
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- Benzyl-piperidine derivatives
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Benzly-piperidine derivatives of formula I and their pharmaceutically acceptable salts are used in the control of psychotic disorders which are caused by damage to the dopamine system, especially schizophrenia. STR1 A is STR2 B is STR3 R 1, R 2 and R 3 are independently hydrogen, amino, nitro, halogen, lower-alkly or lower-alkoxy. R 4, R 5 and R 6 are independently hydrogen, nitro, halogen, lower-alkyl, lower-alkoxy, cyano, trifluoromethyl, amino, lower-alkylamino or di-lower-alkylamino. R 7, R 2 and R 9 are independently hydrogen, amino or nitro.
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- Catalytic processes of oxidation by hydrogen peroxide in the presence of Br2 or HBr. Mechanism and synthetic applications
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The mechanism and the synthetic applications for the oxidation of alcohols, ethers, and aldehydes by H2O2 catalyzed by Bf2 or Br- in a liquid two-phase system (aqueous and organic) are reported. Aliphatic and benzylic primary alcohols and ethers show an opposite behavior, which has been rationalized on the ground of the different electronic configurations of the intermediate alkyl (π-type) and acyl (σ-type) radicals and their influence on enthalpic and polar effects. A two-phase system is particularly useful also for an efficient benzylic bromination by Br2 or Br-; the substitution of the benzyl bromide by OH, OR, and OCOR regenerates Br-, which can be recycled. The evaluation of the relative reactivities of the involved substrates and intermediates has allowed to develop a variety of simple, facile, convenient, and selective syntheses of alcohols, aldehydes, ketones, esters, and benzyl bromides, which fulfill the conditions for practical applications.
- Amati, Alessandro,Dosualdo, Gabriele,Zhao, Lihua,Bravo, Anna,Fontana, Francesca,Minisci, Francesco,Bjorsvik, Hans-Rene
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p. 261 - 269
(2013/09/08)
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- Process for the preparation of intermediates
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A new process for the preparation of 1-chloro-2-(1-chloro-cyclopropyl)-3-(2-chloro-phenyl)-propan-2-ol of the formula STR1 and/or 2-(1-chloro-cyclopropyl)-2-(2-chloro-benzyl)-oxirane of the formula STR2 comprising a) reacting in a first step, 2-chloro-ben
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- Reduction of carbonyl compounds promoted by silicon hydrides under the influence of trimethylsilyl-based reagents
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The synthetic utility of hydrosilanes under the influence of trimethylsilyl-based reagents as new reducing systems is described. 1,1,3,3-Tetramethyldisiloxane (TMDS) reagent in combination with iodotrimethylsilane or bromotrimethylsilane produces alkyl halides from aldehydes in good to excellent yields.Polymethylhydrosiloxane (PMS) in the presence of iodotrimethylsilane also produces benzyl iodides in excellent yields.On the contrary, PMS reagent was found unsuitable for the synthesis of benzyl bromides.Similary, TMDS reagent in combination with trimethylsilyl triflate produces symmetrical ethers from aldehydes without concomitant formation of competitive products.Under similar conditions, PMS reagent failed to provide the expected symmetrical ethers and Friedel-Crafts products were formed.Reduction of quinones to hydroquinones is also described.
- Aizpurua, Jesus M.,Lecea, Begona,Palomo, Claudio
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p. 2342 - 2347
(2007/10/02)
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- SYNTHESIS OF BENZYL HALIDES FROM ALDEHYDES PROMOTED BY HALOSILANES AND 1,1,3,3-TETRAMETHYLDISILOXANE (TMDS).
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Direct synthesis of monoalkyl halides from aldehydes by a new reductive halogenation method is briefly described.
- Aizpurua, Jesus M.,Palomo, Claudio
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p. 1103 - 1104
(2007/10/02)
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- A FACILE METHOD FOR THE CONVERSION OF PRIMARY ALKYL CHLORIDES TO THE CORRESPONDING BROMIDES
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Treatment of several representative primary alkyl chlorides with one equivalent of sodium bromide in 2:1 (v/v) N,N-dimethylformamide : dibromoethane at 100 deg C for several hours resulted in their quantitative conversion to the corresponding bromides.
- Babler, James H.,Spina, Kenneth P.
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p. 1313 - 1320
(2007/10/02)
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- OXIDATION OF o-CHLOROTOLUENE CATALYZED BY COBALT ACETATE AND SODIUM BROMIDE IN ACETIC ACID SOLUTION
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The oxidation of o-chlorotoluene to o-chlorobenzoic acid with oxygen in glacial acetic acid solution in the presence of a mixture of cobalt acetate and soidum bromide was investigated.It was shown that the reaction mechanism changes during the oxidation p
- Belous, N. P.,Tmenov, B. N.,Bespalova, T. P.,Alimova, O. V.,Shcherbina, F. F.
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p. 311 - 314
(2007/10/02)
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- PHOTOCHEMICAL REACTION OF ALCOHOLS - II. IRRADIATION OF AROMATIC ALCOHOLS
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The UV irradiation of aromatic alcohols leads to the formation of several products: carbonyl compounds, ethers, α-glycols and tetra-aryl-1,4-dioxanes.The photoformation of α-glycols is qualitatively and quantitatively compared to the photoreduction of the carbonyl compounds.It is noteworthy that the glycols are formed with a stereochemistry very different depending upon whether the substrate is an alcohol or a carbonyl compound.The structure, configuration and conformation of the 1,4-dioxanes obtained are studied as well as their origin.Other aspects of the photochemistry of the alcohols are analyzed using hydroperoxides as model substrates.
- Balsells, R. Erra,Frasca, A. R.
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p. 2525 - 2538
(2007/10/02)
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