- Nickel-Mediated Enantiospecific Silylation via Benzylic C-OMe Bond Cleavage
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Benzylic stereocenters are found in bioactive and drug molecules, as enantiopure benzylic alcohols have been used to build such a stereogenic center, but are limited to the construction of a C-C bond. Silylation of alkyl alcohols has the potential to build bioactive molecules and building blocks; however, the development of such a process is challenging and unknown. Herein, we describe an unprecedented AgF-assisted nickel catalysis in the enantiospecific silylation of benzylic ethers.
- Balakrishnan, Venkadesh,Murugesan, Vetrivelan,Chindan, Bincy,Rasappan, Ramesh
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supporting information
p. 1333 - 1338
(2021/02/20)
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- Synthesis and Evaluation of Antimicrobial Activities of Novel N-Substituted Indole Derivatives
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Indole motifs are one of the most significant scaffolds in the discovery of new drugs. We have described a synthesis of new N-substituted indole derivatives (1-3), and their in vitro antimicrobial activities were investigated. The synthesis of titled compounds has been demonstrated by utilizing commercially available starting materials. The antibacterial and antifungal activities were performed using new strains of bacteria Staphylococcus aureus, Escherichia coli, and Candida albicans using the disc diffusion method. Notably, the compound 4-(1-(2-(1H-indol-1-yl) ethoxy) pentyl)-N,N-dimethyl aniline (1) was found to be most potent than the other analogues (2 and 3), which has shown higher inhibition than the standard drug chloramphenicol.
- Mahamadalli Shaikh, Tanveer,Debebe, Habtamu
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- Diarylmethanols synthesis by nickel(II)-catalyzed addition of arylboronic acids to aryl aldehydes
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A practical procedure for the addition of arylboronic acids to aromatic aldehydes has been developed in the presence of NiCl2(PPh3)2/1,3-bis-(2,6-diisopropylphenyl)imidazolium chloride (IPr·HCl) system with good yield. Generally, electron-rich and-neutral aryl aldehydes showed excellent reactivity and provided desired products in high yields. This procedure will provide new way to the synthesis of diarylmethanols.
- Bie, Fusheng,Cao, Han,Cui, Haizhu,Li, Tang,Liu, Xuejing,Ma, Jie,Wang, Meng
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supporting information
p. 248 - 253
(2020/04/24)
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- A Direct Br?nsted Acid-Catalyzed Azidation of Benzhydrols and Carbohydrates
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Benzhydryl alcohols were converted into their corresponding diarylazidomethane analogues using azidotrimethylsilane (TMSN3) in the presence of a catalytic amount of a Br?nsted acid HBF4·OEt2. The azidation reactions proceeded in high yields and demonstrated excellent functional group tolerance to electron-donating and electron-withdrawing substituents. In addition, a range of unprotected functional groups including amine, amide, aldehyde and alcohol were well-tolerated. Furthermore, this methodology was successfully applied to carbohydrates for the preparation of the corresponding azide derivatives.
- Regier, Jeffery,Maillet, Robert,Bolshan, Yuri
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p. 2390 - 2396
(2019/04/14)
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- Di(hetero)arylmethanol compound preparation method
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The invention belongs to the field of organic synthesis, and particularly relates to a di(hetero)arylmethanol compound preparation method, wherein the di(hetero)arylmethanol compound is prepared in ahigh-yield manner by using commercially available (hetero)aryl aldehyde and commercially available (hetero)arylboronic acid as raw materials and using a cheap and stable divalent nickel source as a catalyst. According to the present invention, the method improves the shortcomings of harsh reaction conditions, more side reactions, difficult post-treatment and the like caused by the general use of metal reagents, avoids the defects of high cost of catalytic reactions of noble metals such as palladium and the like and difficulty in mass production, has characteristics of mild conditions, convenient operation, low cost, high efficiency and environmental friendliness, and is suitable for practical scale production.
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Paragraph 0047; 0048; 0049; 0065; 0066; 0067
(2019/02/10)
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- Direct allylation of benzyl alcohols, diarylmethanols, and triarylmethanols mediated by XtalFluor-E
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We report the direct allylation of benzyl alcohols, diarylmethanols and triarylmethanols mediated by XtalFluor-E using allyltrimethylsilane. The resulting allylated products are obtained in moderate to high yield.
- Lebleu, Thomas,Paquin, Jean-Fran?ois
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supporting information
p. 442 - 444
(2017/01/10)
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- Coupling of aromatic aldehydes with aryl halides in the presence of nickel catalysts with diazabutadiene ligands
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Nickel catalysts with diazabutadiene ligands promote cross-coupling of benzaldehydes with aryl halides in the presence of zinc as reducing agent, which leads to the corresponding benzhydrols and benzophenones. The benzophenone percentage considerably increases when lithium chloride additive is used.
- Asachenko,Valaeva,Kudakina,Uborsky,Izmer,Kononovich,Voskoboynikov
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p. 456 - 463
(2017/03/08)
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- Catalyst free, three-component approach for unsymmetrical triarylmethanes (TRAMs)
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An efficient catalyst free, three-component, cascade approach has been designed and developed for the rapid assembly of unsymmetrical triarylmethane framework. The strategy employed aromatic aldehydes, Grignard reagents, and neutral aromatics as reaction
- Chinta, Bhavani Shankar,Baire, Beeraiah
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supporting information
p. 5381 - 5384
(2016/11/11)
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- Synergistic stereoselective organocatalysis with indium(III) salts
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The compatibility of indium(III) Lewis acids with water and amines allows their employment in synergistic and cooperative catalysis. Stereoselective organocatalytic SN1-type reactions, in which carbenium ions are generated, are promoted by the presence of indium salts. The peculiar properties of indium salts can be exploited in organocatalysis for the design of water-compatible, benign, green processes. The development of such indium(III)-promoted organocatalytic procedures is the focus of our recent research, a summary of which is presented in this article. Georg Thieme Verlag Stuttgart.New York.
- Gualandi, Andrea,Mengozzi, Luca,Wilson, Claire Margaret,Cozzi, Pier Giorgio
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supporting information
p. 1321 - 1328
(2014/06/09)
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- Mesityllithium and p-(dimethylamino)phenyllithium for the selective alternate trilithiation of the hexaphenylbenzene framework
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We report mesityllithium and p-(dimethylamino)phenyllithium as new valuable lithiating reagents, which realize Br/Li exchange reaction of bromoarenes at relatively high temperature in THF. With these reagents, we established the general and practical protocols for the selective alternate trilithiation of the hexaphenylbenzene framework. This journal is the Partner Organisations 2014.
- Kojima, Tatsuo,Hiraoka, Shuichi
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supporting information
p. 10420 - 10423
(2014/10/15)
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- The palladium-catalyzed addition of aryl- and heteroarylboronic acids to aldehydes
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(Chemical Equation Presented) Reaction of aryl- or heteroarylboronic acids with aldehydes, in the presence of PdCl2 and P(1-Nap)3, afforded carbinol derivatives in good to excellent yields. The efficiency of this reaction was demonstrated by the compatibility with nitro, cyano, acetamido, acetoxy, acetyl, carboxyl, trifluoromethyl, fluoro, and chloro groups and the possibility of involving aliphatic aldehyde or hindered substrates. Moreover, the rigorous exclusion of air/moisture is not required in these transformations.
- Qin, Changming,Wu, Huayue,Cheng, Jiang,Chen, Xi'an,Liu, Miaochang,Zhang, Weiwei,Su, Weike,Ding, Jinchang
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p. 4102 - 4107
(2008/02/04)
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- Disproportionation reaction of diarylmethylisopropyl ethers: a versatile access to diarylmethanes from diarylcarbinols speeded up by the use of microwave irradiation
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An efficient synthesis of diarylmethanes under classical thermal conditions and under microwave heating is described from diarylcarbinols via a new disproportionation reaction. The key step involves a selective hydride transfer of isopropyl ether intermed
- L'Hermite, Nathalie,Giraud, Anne,Provot, Olivier,Peyrat, Jean-Fran?ois,Alami, Mouad,Brion, Jean-Daniel
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p. 11994 - 12002
(2007/10/03)
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- Highly efficient reagents for Br/Mg exchange
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(Chemical Equation Presented) The conversion of electron-rich aryl bromides into the corresponding Grignard compounds proceeds within 2 h at 25°C in the presence of 0.55 equivalents of the new reagent sBu2Mg· LiCl. The high reactivity of magnes
- Krasovskiy, Arkady,Straub, Bernd F.,Knochel, Paul
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p. 159 - 162
(2007/10/03)
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- Rhodium-catalyzed addition of arylstannanes to carbon-heteroatom double bond
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The addition of arylstannanes to the carbon-heteroatom double bond in the presence of a catalytic amount of a cationic rhodium complex ([Rh(cod)(MeCN)2]BF4) was examined. The reactions of aldehydes, α-dicarbonyl compounds, and N-substituted aldimines with the arylstannanes gave corresponding alcohols, α-hydroxy carbonyl compounds, and amines, respectively. An arylrhodium complex generated by the transmetalation with the arylstannane was probably the active catalytic species.
- Oi, Shuichi,Moro, Mitsutoshi,Fukuhara, Hiroe,Kawanishi, Takanori,Inoue, Yoshio
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p. 4351 - 4361
(2007/10/03)
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- Process for producing benzhydrols
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There is disclosed a process for producing benzhydrls by reacting an arylmetal compound with an aromatic aldehyde. According to this process, benzhydrols useful as raw materials for medicines and photopolymerization initiators can be produced in a high yield and industrially advantageously.
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- First General Synthesis of (p-Nitroaryl)diarylmethanes via Vicarious Nucleophilic Substitution of Hydrogen
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A general regiospecific method for the synthesis of (p-nitroaryl)diarylmethanes has been developed starting from diarylmethanols and 2- and/or 3-substituted nitrobenzenes. This utilizes the quantitative condensation between benzotriazole and diarylmethanols under acidic catalysis and in the presence of perfluorocarbon fluids, followed by vicarious nucleophilic substitution of the resulting diarylmethylbenzotriazoles upon nitrobenzenes in moderate to high yield, Oxidative nucleophilic substitution of hydrogen is observed as a side process. These vicarious nucleophilic substitutions complement Friedel-Crafts reactions for the synthesis of triarylmethanes.
- Katritzky, Alan R.,Toader, Dorin
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p. 4137 - 4141
(2007/10/03)
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- Synthesis of Long Chain Malachite Green Leuco Base (LMGH) and Its Spectroscopic Study in Organic Solvents and Ionic Micellar Solutions
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The synthesis of long chain malachite green leuco base (LMGH) is reported.The absorption spectra of LMGH in different solvents seem to be independent of the solvent polarity (dielectric constant), while the emission spectra are dependent on it.Slight fluorescence self-quenching of LMGH in methanolic solution appears at a concentration of ca. 4*10-5 mol dm-3 and it becomes the dominant factor above 2*10-4 mol dm-3.The effect of the long chain on the basicity of LMGH relative to that of malachite green leuco base (MGH) can be revealed by the fluorescence quenchi ng of both compounds by Fe3+.The quenching process obeys a static type of mechanism, which is followed by an electron transfer of LMGH to Fe3+.The fluorescence quenching efficiency of micellized LMGH by Fe3+ is very dependent on the charge of the micelle, and is most effective in sodium dodecyl sulfate (SDS) micelle.The color appearance of the dye from LMGH upon mixing with Fe3+, is easily observed in methanol, but not in SDS micelle.The critical micelle concentrations (cmc) of anionic (SDS) and cationic (hexadecyltrimethylammonium chloride, CTAC) micelles have been estimated using LMGH as a probe.
- El-Shishtawy, Reda M.,Fukunishi, Koushi
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p. 929 - 934
(2007/10/02)
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- A Reinvestigation of the Meerwein-Ponndorf-Verley Reduction: A Highly Efficient Variation Using Zirconium Catalysts
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A new variation of the Meerwein-Ponndorf-Verley reduction based on mechanistic considerations is presented.Under optimized conditions 1-(4-dimethylaminophenyl)ethanol was used as the reducing alcohol (2-4 equiv.), Zr(O-tBu)4 as the catalyst (0.2 equiv.), and toluene or cyclohexane as the solvent.Aldehydes and ketones (if not extremely sterically hindered) were reduced to the corresponding alcohols at room temperature mostly within 2-4 h in essentially quantitative yield. α,β-Unsaturated carbonyl compounds cleanly react in a 1,2-mode to afford the corresponding allylic alcohols. - Key Words: Reductions / Meerwein-Ponndorf-Verley reaction / Catalysis / Zirconium tetra-tert-butoxide / β-Hydride shift / Kinetics
- Knauer, Birgit,Krohn, Karsten
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p. 677 - 684
(2007/10/02)
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- Meta Functionalization of Anilines and Phenol
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Base-promoted proton abstraction from ?-(N-tert-butyldimethylsilyl-N-methylaniline)chromium tricarbonyl (3) took place predominantly at the meta position and variously meta-substituted N-methylacetanilides 4 were obtained after reactions with electrophiles followed by oxidative decomplexation and N-acetylation.Application of the present method to variously N,N-disubstituted anilines 5 and phenols 7 was then examined and the corresponding meta substituted anilines 6 and phenol 9 were obtained.Keywords - metalation of aromatic ring; chromium tricarbonyl complex; tert-butyl dimethylsilyl protecting group; meta-substituted anilines; meta-substituted phenol; electrophilic substitution
- Fukui, Mineo,Ikeda, Toshiya,Oishi, Takeshi
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p. 466 - 475
(2007/10/02)
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