- Nanomagnetic catalysis (Fe3O4@S–TiO2): a novel magnetically nano catalyst for the synthesis of new highly substituted tetrahydropyridine derivatives under solvent-free conditions
-
A novel nanomagnetic catalyst (Fe3O4@S–TiO2) was prepared by the hydrothermal method. At the first, Fe3O4 nanoparticles were synthesized, then iron oxide nanoparticles (IONPs) were dispersed in ethano
- Nezami, Zahra,Eshghi, Hossein
-
p. 1997 - 2008
(2021/01/20)
-
- Carbon monoxide-driven osmium catalyzed reductive amination harvesting WGSR power
-
Herein, we present the first example of Os-catalyzed efficient reductive amination under water-gas shift reaction conditions. The developed catalytic systems are formedin situin aqueous solutions, employ as small as 0.0625 mol% osmium and are capable of delivering reductive amination products for a broad range of aliphatic and aromatic carbonyl compounds and amines. The scope of the reaction, active catalytic systems, possible limitations of the method and DFT-supported mechanistic considerations are discussed in detail in the manuscript.
- Afanasyev, Oleg I.,Biriukov, Klim O.,Chusov, Denis,Godovikova, Maria,Loginov, Dmitry A.,Nelyubina, Yulia V.,Tsygankov, Alexey A.,Vasilyev, Dmitry V.,Vinogradov, Mikhail M.
-
p. 4922 - 4930
(2021/07/26)
-
- Iron-Catalyzed Hydrogen Transfer Reduction of Nitroarenes with Alcohols: Synthesis of Imines and Aza Heterocycles
-
A straightforward and selective reduction of nitroarenes with various alcohols was efficiently developed using an iron catalyst via a hydrogen transfer methodology. This protocol led specifically to imines in 30-91% yields, with a good functional group tolerance. Noticeably, starting from o-nitroaniline derivatives, in the presence of alcohols, benzimidazoles can be obtained in 64-72% yields when the reaction was performed with an additional oxidant, DDQ, and quinoxalines were prepared from 1,2-diols in 28-96% yields. This methodology, unprecedented at iron for imines, also provides a sustainable alternative for the preparation of quinoxalines and benzimidazoles.
- Wu, Jiajun,Darcel, Christophe
-
p. 1023 - 1036
(2021/01/09)
-
- Enantioselective Direct anti-Selective Mannich-type Reactions Catalyzed by 3-Pyrrolidinecarboxylic Acid in the Presence of Potassium Carbonate: Addition of Potassium Carbonate Improves Enantioselectivities
-
Mannich-type reactions of cyclohexanone and related six-membered-ring ketones with N-p-methoxyphenyl-protected imines of arylaldehydes catalyzed by 3-pyrrolidinecarboxylic acid in the presence of K2CO3 that afford anti-isomers of the Mannich products with
- Garg, Yuvraj,Tanaka, Fujie
-
supporting information
p. 4542 - 4546
(2020/06/08)
-
- First sonochemical, simple and solvent-free synthesis of chiral tert-butanesulfinimines using silica supported p-toluenesulfonic acid
-
A solvent-free, versatile procedure has been developed for the effective synthesis of tert-butanesulfinylimines of a variety of aldehydes using chiral tert-butanesulfinamides under green, sonochemical conditions. This method utilizes silica supported p-to
- Appa, Rama Moorthy,Lakshmidevi, Jangam,Siva Prasad, Sana,Muralidhar, Baitinti,Ramesh Naidu, Bandameeda,Narasimhulu, Manchala,Venkateswarlu, Katta
-
supporting information
p. 56 - 64
(2019/01/18)
-
- Visible-Light-Mediated, Chemo- and Stereoselective Radical Process for the Synthesis of C-Glycoamino Acids
-
An approach for efficient synthesis of C-glycosyl amino acids is described. Different from typical photoredox-catalyzed reactions of imines, the new process follows a pathway in which α-imino esters serve as electrophiles in chemoselective addition reactions with nucleophilic glycosyl radicals. The process is highlighted by the mild nature of the reaction conditions, the highly stereoselectivity attending C-C bond formation, and its applicability to C-glycosylations using both armed and disarmed pentose and hexose derivatives.
- Ji, Peng,Zhang, Yueteng,Wei, Yongyi,Huang, He,Hu, Wenbo,Mariano, Patrick A.,Wang, Wei
-
supporting information
p. 3086 - 3092
(2019/05/01)
-
- Organocatalytic Mukaiyama Mannich Reactions of 2,5-Bis(trimethylsilyloxy)furan
-
The organocatalytic synthesis of densely substituted mono- and bis-?-lactams involving the Mukaiyama Mannich addition of 2,5-bis(trimethylsilyloxy)furan to imines is described. Use of a ditoluenesulfonylimide catalyst produces ?-lactams from monoaddition, whereas a more acidic catalyst (triflic acid) produces fused bis-lactams from double addition. Optimized organocatalytic conditions allow for the selective synthesis of either desired core as well as the one-pot, multicomponent assembly of the trisubstituted monolactams from aldehydes, amines, and bis-trimethylsilyloxyfuran. An examination of chiral acids found these organocatalysts to be highly active and diastereoselective in the monoaddition reaction, albeit with no enantioselectivity.
- Laws, Stephen W.,Howard, Sara Y.,Mato, Raquel,Meng, Shuyu,Fettinger, James C.,Shaw, Jared T.
-
supporting information
p. 5073 - 5077
(2019/07/03)
-
- Iron-Catalyzed Nitrene Transfer Reaction of 4-Hydroxystilbenes with Aryl Azides: Synthesis of Imines via C=C Bond Cleavage
-
C=C bond breaking to access the C=N bond remains an underdeveloped area. A new protocol for C=C bond cleavage of alkenes under nonoxidative conditions to produce imines via an iron-catalyzed nitrene transfer reaction of 4-hydroxystilbenes with aryl azides is reported. The success of various sequential one-pot reactions reveals that the good compatibility of this method makes it very attractive for synthetic applications. On the basis of experimental observations, a plausible reaction mechanism is also proposed.
- Peng, Yi,Fan, Yan-Hui,Li, Si-Yuan,Li, Bin,Xue, Jing,Deng, Qing-Hai
-
p. 8389 - 8394
(2019/10/16)
-
- One-pot sequential multicomponent reaction between: In situ generated aldimines and succinaldehyde: Facile synthesis of substituted pyrrole-3-carbaldehydes and applications towards medicinally important fused heterocycles
-
An efficient sequential multi-component method for the synthesis of N-Arylpyrrole-3-carbaldehydes has been developed. This reaction involved a proline-catalyzed direct Mannich reaction-cyclization sequence between succinaldehyde and in situ generated Ar/H
- Singh, Anoop,Mir, Nisar A.,Choudhary, Sachin,Singh, Deepika,Sharma, Preetika,Kant, Rajni,Kumar, Indresh
-
p. 15448 - 15458
(2018/05/03)
-
- Enantioselective synthesis of 1,2,5,6-tetrahydropyridines (THPs): Via proline-catalyzed direct Mannich-cyclization/domino oxidation-reduction sequence: Application for medicinally important N-heterocycles
-
An enantioselective multi-component synthesis of 1,2,5,6-tetrahydropyridines (THPs) has been developed through a one-pot domino-process. This transformation proceeds through proline-catalyzed direct Mannich reaction-cyclization of glutaraldehyde with in s
- Ramaraju, Panduga,Mir, Nisar A.,Singh, Deepika,Kumar, Indresh
-
p. 60422 - 60432
(2016/07/11)
-
- Formal [4+2]-annulation of vinyl azides with N-unsaturated aldimines
-
Highly functionalized quinolines and pyridines could be synthesized by BF3?OEt2-mediated reactions of vinyl azides with N-aryl and N-alkenyl aldimines, respectively. The reaction mechanism could be characterized as formal [4+2]-annulation, including unprecedented enamine-type nucleophilic attack of vinyl azides to aldimines and subsequent nucleophilic cyclization onto the resulting iminodiazonium ion moieties.
- Zhu, Xu,Wang, Yi-Feng,Zhang, Feng-Lian,Chiba, Shunsuke
-
supporting information
p. 2458 - 2462
(2014/10/15)
-
- Iodine(III)-mediated C-H alkoxylation of aniline derivatives with alcohols under metal-free conditions
-
The development of a novel intermolecular oxidative C-H alkoxylation of aniline derivatives is described under metalfree conditions with high reaction rates at ambient temperature. In the presence of an I(III) oxidant, a range of aldehydes, anilines, and alcohol substrates undergo three-component coupling to produce synthetically useful alkoxyl-substituted N-arylimines. The preliminary mechanism investigations revealed that the transformation proceeds via imines as intermediates.
- Jiang, Qing,Wang, Jing-Yu,Guo, Cancheng
-
p. 8768 - 8773
(2014/12/12)
-
- Reversible aryl migrations in metallated ureas: Controlled inversion of configuration at a quaternary carbon atom
-
Deprotonation with strong bases of N-vinyl ureas carrying an N′-aryl substituent leads to migration of the N′-aryl group from N to C via an allyllithium; with weaker bases and electron-deficient aryl rings the direction of the migration reverses, and aryl
- Tetlow, Daniel J.,Vincent, Mark A.,Hillier, Ian H.,Clayden, Jonathan
-
supporting information
p. 1548 - 1550
(2013/03/13)
-
- A synthesis of α-amino acids via direct reductive carboxylation of imines with carbon dioxide
-
A method for the synthesis of α-amino acids by direct reductive carboxylation of aromatic imines with CO2 is described. The protocol employs readily available commercial reagents and serves as a one-step alternative to the Strecker synthesis. The Royal Society of Chemistry 2013.
- Sathe, Ajay A.,Hartline, Douglas R.,Radosevich, Alexander T.
-
supporting information
p. 5040 - 5042
(2013/06/05)
-
- The use of samarium or sodium iodide salts as an alternative for the aza-Henry reaction
-
A novel reaction of bromonitromethane with a variety of imines in very mild conditions promoted by SmI2 and NaI to afford nitroamines or bromonitroamines is described. When these reactions were performed on sugar-based imines, the corresponding
- Rodríguez-Solla, Humberto,Concellón, Carmen,Alvaredo, Noemí,Soengas, Raquel G.
-
experimental part
p. 1736 - 1744
(2012/03/10)
-
- Chiral phosphoric acid catalyzed inverse-electron-demand aza-Diels-Alder reaction of isoeugenol derivatives
-
Highly enantio- and diastereoselective three-component inverse electron-demand aza-Diels-Alder reaction of aldehydes, anilines, and isoeugenol derivatives catalyzed by a chiral phosphoric acid catalyst are reported. A wide variety of 2,3,4-trisubstituted tetrahydroquinolines containing an aryl group at the 4-position were obtained in a one-pot process with good to high yields and excellent stereoselectivities (>95:5 dr and up to >99% ee).
- He, Long,Bekkaye, Mathieu,Retailleau, Pascal,Masson, Géraldine
-
supporting information; experimental part
p. 3158 - 3161
(2012/08/07)
-
- Synthesis of optically pure vic-sulfanyl amines mediated by a remote sulfinyl group
-
Enantiomerically pure syn-1,2-diaryl-1,2-sulfanylamine derivatives can be obtained in a completely stereoselective manner by reaction of the benzylcarbanion Li-(S)-1 with N-phenyl (or PMP)-arylidene aldimines and further desulfinylation with t-BuLi. Theoretical studies at the DFT (mPW1PW91) level with the CPCM model, by using the Gaussian09 program, provide a good explanation for the stereochemical results.
- Arroyo, Yolanda,Sanz-Tejedor, M. Ascension,Alonso, Ines,Garcia-Ruano, Jose L.
-
body text
p. 4534 - 4537
(2011/10/09)
-
- Total regioselective transformation of aromatic aziridine 2-carboxamides into 2-aminoamides promoted by active manganese
-
(Figure Presented) A novel, totally regioselective transformation of aromatic N-4-methoxyphenylaziridine 2-carboxamides into 2-aminoamides promoted by active manganese (Mn) is reported. a-Amino ketones can be readily obtained by reaction of morpholine-der
- Concellon, Jose M.,Rodriguez-Solla, Humberto,Del Amo, Vicente,Diaz, Pamela
-
supporting information; experimental part
p. 2407 - 2410
(2010/06/21)
-
- An efficient and convenient synthesis of ethyl 1-(4-Methoxyphenyl)-5- phenyl-1H-1,2,3-triazole-4-carboxylate
-
The "click chemistry" of using organic azides and terminal alkynes is arguably the most efficient and straightforward route to the synthesis of 1,2,3-triazoles. In this paper, an alternative and direct access to ethyl 1-(4-methoxyphenyl)-5-phenyl-1H-1,2,3
- Chen, Jung-Hsuan,Liu, Shuan-Ru,Chen, Kwunmin
-
experimental part
p. 328 - 333
(2010/07/05)
-
- One-pot synthesis and fluorescence properties of 2-arylquinolines
-
The one-pot synthesis of 2-arylquinoline with arylamines, arylaldehyde, and 1,1-diethoxyethane were studied using a catalytic amount ytterbium triflate. Various 2-arylquinolines showed fluorescence properties and the fluorescence was quenched by introduci
- Sueki, Shunsuke,Okamoto, Chiharu,Shimizu, Isao,Seto, Keisuke,Furukawa, Yukio
-
supporting information; experimental part
p. 385 - 390
(2010/07/09)
-
- Synthesis of densely substituted trans-configured 4-acylated piperidine-2,4-diones as 3:1 Adducts of imines and ketenes
-
An operationally simple method is described to form densely substituted diastereomerically pure trans-configured and potentially biologically interesting 5,6-dihydropyridone derivatives as 3:1 adducts of ketenes formed in situ from acyl bromides and aromatic imines.
- Cabrera, Jose,Hellmuth, Tina,Peters, Rene
-
experimental part
p. 4326 - 4329
(2010/09/03)
-
- Room temperature metathesis of aryl isocyanates and aromatic aldehydes catalyzed by group(IV) metal alkoxides: An experimental and computational study
-
Aromatic aldehydes and aryl isocyanates do not react at room temperature. However, we have shown for the first time that in the presence of catalytic amounts of group(IV) n-butoxide, they undergo metathesis at room temperature to produce imines with the extrusion of carbon dioxide. The mechanism of action has been investigated by a study of stoichiometric reactions. The insertion of aryl isocyanates into the metal n-butoxide occurs very rapidly. Reaction of the insertion product with the aldehyde is responsible for the metathesis. Among the n-butoxides of group(IV) metals, Ti(OnBu)4 (8aTi) was found to be more efficient than Zr(OnBu)4 (8aZr) and Hf(OnBu)4 (8aHf) in carrying out metathesis. The surprisingly large difference in the metathetic activity of these alkoxides has been probed computationally using model complexes Ti(OMe)4 (8bTi), Zr(OMe)4 (8bZr) and Hf(OMe)4 (8bHf) at the B3LYP/LANL2DZ level of theory. These studies indicate that the insertion product formed by Zr and Hf are extremely stable compared to that formed by Ti. This makes subsequent reaction of Zr and Hf complexes unfavorable.
- Kumar, Akshai,Samuelson, Ashoka G.
-
experimental part
p. 338 - 345
(2010/05/01)
-
- Proline-mediated enantioselective construction of tetrahydropyridines via a cascade Mannich-type/intramolecular cyclization reaction
-
A highly diastereo- and enantioselective synthesis of 2,3-disubstituted tetrahydropyridines was accomplished via a proline-mediated cascade Mannich-type/intramolecular cyclization reaction from preformed N-PMP (p-methoxyphenyl) aldimines and inexpensive aqueous tetrahydro-2H-pyran-2,6- diol.
- Han, Rong-Gang,Wang, Yao,Li, Yu-Ye,Xu, Peng-Fei
-
supporting information; experimental part
p. 1474 - 1478
(2009/07/18)
-
- Enantioselective direct aza hetero-Diels-Alder reaction catalyzed by chiral Bronsted acids
-
(Chemical Equation Presented) The first chiral Bronsted acid-catalyzed asymmetric direct aza hetero-Diels-Alder reaction has been described. The phosphoric acids, prepared from binol and H8-binol derivatives, have shown catalytic ability for th
- Liu, Hua,Cun, Lin-Feng,Mi, Ai-Qiao,Jiang, Yao-Zhong,Gong, Liu-Zhu
-
p. 6023 - 6026
(2007/10/03)
-
- Expedient synthesis of chiral 1,2- and 1,4-diamines: Protecting group dependent regioselectivity in direct organocatalytic asymmetric Mannich reactions
-
Organocatalytic asymmetric Mannich reaction of protected amino ketones with imines in the presence of an L-proline-derived tetrazole catalyst afforded diamines with excellent yields and enantioselectivities of up to 99%. The amino ketone protecting group
- Chowdari, Naidu S.,Ahmad, Moballigh,Albertshofer, Klaus,Tanaka, Fujie,Barbas III, Carlos F.
-
p. 2839 - 2842
(2007/10/03)
-
- Substituent cross-interaction effects on the electronic character of the C=N bridging group in substituted benzylidene anilines - Models for molecular cores of mesogenic compounds. A 13C NMR study and comparison with theoretical results
-
13C NMR chemical shifts δc(C=N) were measured in CDCl 3 for a wide set of mesogenic molecule model compounds, viz. the substituted benzylidene anilines P-X-C6H4CH=NC 6H4-p-Y (X = NO2, CN, CF3, F, Cl, H, Me, MeO, or NMe2; Y = NO2, CN, F, Cl, H, Me, MeO, or NMe2). The substituent dependence of δc(C=N) was used as a tool to study electronic substituent effects on the azomethine unit. The benzylidene substituents X have a reverse effect on δc(C=N): electron-withdrawing substituents cause shielding, while electron-donating ones behave oppositely, the inductive effects clearly predominating over the resonance effects. In contrast, the aniline substituents Y exert normal effects: electron-withdrawing substituents cause deshielding, while electron-donating ones cause shielding of the C=N carbon, the strengths of the inductive and resonance effects being closely similar. Additionally, the presence of a specific cross-interaction between X and Y could be verified. The electronic effects of the neighboring aromatic ring substituents systematically modify the sensitivity of the C=N group to the electronic effects of the benzylidene or aniline ring substituents. Electron-withdrawing substituents on the aniline ring decrease the sensitivity of δc(C=N) to the substitution on the benzylidine ring, while electron-donating substituents have the opposite effect. In contrast, electron-withdrawing substituents on the benzylidene ring increase the sensitivity of δc(C=N) to the substituent on the aniline ring, while electron-donating substituents act in the opposite way. These results can be rationalized in terms of the substituent-sensitive balance of the electron delocalization (mesomeric effects). The present NMR characteristics are discussed as regards the computational literature data. Valuable information has been obtained on the effects of the substituents on the molecular core of the mesogenic model compounds.
- Neuvonen, Helmi,Neuvonen, Kari,Fueloep, Ferenc
-
p. 3141 - 3148
(2007/10/03)
-
- Cu(OTf)2 or Et3N-catalyzed three-component condensation of aldehydes, amines and cyanides: a high yielding synthesis of α-aminonitriles
-
Copper(II) triflate or Et3N have been found to catalyze, under ambient conditions, the addition of a cyanide anion, such as trimethylsilyl cyanide or acetone cyanohydrin, onto in situ generated imines, furnishing α-aminonitriles in excellent yi
- Paraskar, Abhimanyu S.,Sudalai, Arumugam
-
p. 5759 - 5762
(2007/10/03)
-
- Aryliminodimagnesium Reagents. XI. Two-Electron Oxidation of the Reagent Molecules in the Reaction with Some Oxidizing Agents and with Strongly Push-Pull Substituted α-Benzylideneacetophenones
-
The reactions of an aryliminomagnesium reagent (ArN(MgBr)2) with four oxidizing agents ((i): I2, OsO4, C6H5IO2, I2O5) and four push-pull substituted α-benzylideneacetophenones (ii) were examined.In the reactions with (i), the maximum yield of sym-azobenzene was 50percent.In the reactions with (ii), in addition to products formed via condensation and the typical radical processes, unexpected products formed via cleavages of C=C and Cβ-H bonds were observed.Summarizing these results, a pathway involving the formation of arylnitrene-like species via disproportionation of arylaminyl radicals has been proposed.
- Okubo, Masao,Yoshida, Shunsei,Egami, Yoshiji,Matsuo, Koji,Nagase, Shigeru
-
p. 1741 - 1746
(2007/10/02)
-