- Cobalt-Catalyzed Deoxygenative Hydroboration of Nitro Compounds and Applications to One-Pot Synthesis of Aldimines and Amides
-
The commercially available and bench-stable Co(acac)2 ligated with bis[(2-diphenylphosphino)phenyl] ether (dpephos) was employed for selective room temperature hydroboration of nitro compounds with HBPin (TOF up to 4615 h?1), tolerating halide, hydroxy, amino, ether, ester, lactone, amide and heteroaromatic functionalities. These reactions offered a direct access to a variety of N-borylamines RN(H)BPin, which were in situ treated with aldehydes and carboxylic acids to produce a series of aldimines and secondary carboxamides without the need for dehydrating and/or coupling reagents. Combination of these transformations in a sequential one-pot manner allowed for direct and selective synthesis of aldimines and secondary carboxamides from readily available and inexpensive nitro compounds.
- Gudun, Kristina A.,Zakarina, Raikhan,Segizbayev, Medet,Hayrapetyan, Davit,Slamova, Ainur,Khalimon, Andrey Y.
-
p. 601 - 611
(2021/11/30)
-
- Photoredox-Catalyzed Synthesis of α-Amino Acid Amides by Imine Carbamoylation
-
An operationally simple protocol for the photocatalytic carbamoylation of imines is reported. Easily available, bench-stable 4-amido Hantzsch ester derivatives serve as precursors to carbamoyl radicals that undergo rapid addition to N-aryl imines. The reaction proceeds under blue light irradiation in the presence of the photocatalyst 3DPAFIPN and Br?nsted/Lewis acid additives. Mechanistic studies indicated a photoredox mechanism that involves carbamoyl radicals.
- Cardinale, Luana,Schmotz, Mattis-Ole W. S.,Konev, Mikhail O.,Jacobi von Wangelin, Axel
-
supporting information
p. 506 - 510
(2022/01/20)
-
- Functional POM-catalyst for selective oxidative dehydrogenative couplings under aerobic conditions
-
Development of selective and efficient reusable catalytic systems for sustainable chemical production under benign conditions is attractive and received much attention. Herein, we report a rod-shaped octadecyl trimethylammonium functionalized Keggin-type polyoxometalate [PMO12O40] hybrids (OTA-POM) as an efficient heterogeneous catalyst for selective oxidative dehydrogenative couplings under aerobic conditions without any additive or external base. The catalyst recovery and subsequent five successive recyclability studies of hybrid POM confirms the heterogeneous nature of present catalytic system.
- Samaraj, Elavarasan,Balaraman, Ekambaram,Manickam, Sasidharan
-
-
- Visible-Light-Induced Cycloaddition of α-Ketoacylsilanes with Imines: Facile Access to β-Lactams
-
We report the synthesis of β-lactams from α-ketoacylsilanes and imines, which proceeds via a formal [2+2] photochemical cycloaddition with in situ generation of siloxyketene. This mild and operationally simple reaction proceeds in an atom-economic fashion with broad substrate scope, including aldimines, ketimines, hydrazones, and fused nitrogen heterocycles, affording a variety of important β-lactams with satisfactory diastereoselectivities in most cases. This reaction also features good functional-group tolerance, facile scalability and product diversification. Experimental and computational studies suggest that α-ketoacylsilanes can serve as photochemical precursors by engaging in a 1,3 silicon shift to the distal carbonyl group.
- Ye, Jian-Heng,Bellotti, Peter,Paulisch, Tiffany O.,Daniliuc, Constantin G.,Glorius, Frank
-
supporting information
p. 13671 - 13676
(2021/05/11)
-
- Aza-peterson olefinations: Rapid synthesis of (E)-alkenes
-
An aza-Peterson olefination methodology to access 1,3-dienes and stilbene derivatives from the corresponding allyl- or benzyltrimethylsilane is described. Silanes can be deprotonated using Schlosser's base and added to N -phenyl imines or ketones to directly give the desired products in high yields.
- Britten, Thomas K.,Basson, Ashley J.,Roberts, Dean D.,McLaughlin, Mark G.
-
p. 3535 - 3544
(2021/06/03)
-
- A Cu-BTC metal-organic framework (MOF) as an efficient heterogeneous catalyst for the aerobic oxidative synthesis of imines from primary amines under solvent free conditions
-
A Cu-BTC (MOF-199) [copper(ii)-benzene-1,3,5-tricarboxylate] catalyst has been synthesized and evaluated for imine synthesis from amine compounds under neat conditions. The performance of the Cu-BTC MOF was significantly higher than that of the CuO supported on Al2O3, TiO2 and SiO2 catalysts. The role of surface Lewis acid sites on the catalyst in the formation of imine products was illustrated by the pyridine-IR studies. The recovered Cu-BTC catalyst demonstrated consistent activity for five cycles under similar experimental conditions. The physicochemical properties of the catalysts were analyzed by XRD, BET-SA, FT-IR, UV-DRS, SEM, TEM, XPS and pyridine adsorbed DRIFT spectroscopy.
- Venu, Boosa,Shirisha, Varimalla,Vishali, Bilakanti,Naresh, Gutta,Kishore, Ramineni,Sreedhar, Inkollu,Venugopal, Akula
-
supporting information
p. 5972 - 5979
(2020/04/27)
-
- Retraction: Harnessing Thiol as a Benzyl Reagent for Photocatalytic Reductive Benzylation of Imines (Organic Letters DOI: 10.1021/2Facs.orglett.0c00065)
-
The authors retract this article after finding in subsequent studies that the quality of the purchased catalysts has a notable impact on the reproducibility of the results. Accordingly, the authors note that additional work is necessary to understand the
- Zhang, Jinghui,Zhang, Muliang
-
supporting information
p. 2112 - 2112
(2020/02/15)
-
- Cu/Ni-doped sulfated zirconium oxide immobilized on CdFe2O4 NPs: a cheap, sustainable and magnetically recyclable inorgano-catalyst for the efficient preparation of α-aminonitriles in aqueous media
-
Abstract: A new multifunctional bimetallic nanocatalyst was prepared by immobilization of Cu/Ni-doped sulfated zirconium oxide on magnetic cadmium ferrite (CdFe2O4@SiO2@ZrO2/SO42?/Cu/Ni) and used as an efficient recyclable catalyst for one-pot as well as stepwise preparation of α-aminonitriles under mild conditions. The magnetic nanocatalyst was characterized by FTIR, TGA, VSM, XRD, EDX, FE-SEM, and TEM analyses. Also, the surface acidity of the catalyst was measured by pyridine adsorption assay. The catalyst possesses various active sites which could catalyst a variety of aromatic and aliphatic aldehydes to the corresponding α-amionitriles under moderate to high yields in the presence of aniline. Furthermore, transformation of ketones to the desired α-amionitriles and some bis-aminonitriles was also performed by this method. The catalyst could be readily recovered from the reaction mixture and reused for several times without significant loss of activity. Graphic abstract: A general and efficient method has been developed for transformation of a variety of aliphatic, aromatic aldehydes and ketones to the corresponding α-aminonitriles using a multifunctional recyclable CdFe2O4@SiO2@ZrO2/SO42?/Cu/Ni nanocatalyst.[Figure not available: see fulltext.]
- Nasseri, Mohammad Ali,Ramezani-Moghadam, Simin,Kazemnejadi, Milad,Allahresani, Ali
-
p. 4233 - 4256
(2020/07/08)
-
- Rational Design of Cobalt-Platinum Alloy Decorated Cobalt Nanoparticles for One-Pot Synthesis of Imines from Nitroarenes and Aldehydes
-
Developing high-performance heterogeneous catalysts for one-pot reductive amination reactions is critically important for pharmaceutical and agrochemical synthetic industries. In this work, N-doped carbon nanotubes supported CoPt alloy decorated Co nanoparticles (NPs) are successfully fabricated. As a consequence, the resultant catalyst exhibits desirable activity, selectivity and stability toward the one-pot synthesis of imines. More importantly, the extensive experimental studies and density function theory (DFT) calculations results reveal that the high catalytic activity of the catalyst is mainly due to the co-existence of CoPt alloy NPs and Co NPs with Co?Nx active sites. The high selectivity of imines could be ascribed to the following aspects: (1) competitively preferred adsorption of nitroarenes to avoid side-hydrogenation of aldehydes; (2) weakened adsorption of imines to minimize its over-hydrogenation. This work may provide a promising direction and strategy to design high-performance reductive amination catalysts for industrial applications.
- Gong, Wanbing,Han, Miaomiao,Chen, Chun,Lin, Yue,Wang, Guozhong,Zhang, Haimin,Zhao, Huijun
-
p. 5948 - 5958
(2020/10/02)
-
- An Efficient Mesoporous Cu-Organic Nanorod for Friedl?nder Synthesis of Quinoline and Click Reactions
-
Within the green chemistry context, heterogeneous catalysis for the synthesis of N-heterocycles from renewable resources using non-precious metals has garnered great interest in terms of economic and environmental perspectives. Herein, we present a triazine functional hierarchical mesoporous organic polymer (HMOP) with nanorod morphology together with large BET surface area ~1218 m2 g?1, huge pore volumeγτ“;6 mL g?1 and dual micro/mesopore architectures. Subsequent Cu-coordination with nitrogen atoms of the HMOP provides a robust catalyst (Cu-HMOP) to accomplish multi-step cascade reactions for preparation of N-heterocycles by different routes. For instance, the Cu-HMOP efficiently catalyzes one-pot sequential multi-step oxidative dehydrogenative coupling of 2-aminobenzyl alcohol with diverse aromatic ketones to afford corresponding quinolines in excellent isolated yields (up to 97 %). Secondly, the present catalyst exhibits good aerobic oxidative dehydrogenation activity of amines to imines. Thirdly, for “click” reaction involving azides-alkynes, the Cu-HMOP produced quantitative yield for 1,4-disubstituted 1,2,3-triazole derivatives at room temperature using water as solvent. Verification of active metal leaching by a hot filtration test as well as reusability of the retrieved Cu-HMOP catalysts shows a consistent activity in the multi-component quinoline synthesis as model reaction.
- Elavarasan, Samaraj,Bhaumik, Asim,Sasidharan, Manickam
-
p. 4340 - 4350
(2019/08/12)
-
- 2,4,6-Trihydroxybenzoic Acid-Catalyzed Oxidative Ugi Reactions with Molecular Oxygen via Homo- And Cross-Coupling of Amines
-
Metal-free, oxidative four-component Ugi reactions (U-4CRs) were conducted to synthesize dipeptides from two different amines, isocyanides, and carboxylic acids using 2,4,6-trihydroxybenzoic acid catalyst in O2 atmosphere. The organocatalytic U-4CRs proceed via oxidative cross-coupling of benzylamines with other aliphatic or aromatic amines to form imines, followed by condensation with isocyanides and carboxylic acids. The U-4CRs via cross-coupling of amines are rare, and the simple, metal-free procedures are advantageous for further applications in drug and heterocycle syntheses.
- Dong, Chun-Ping,Uematsu, Akinori,Kumazawa, Shun,Yamamoto, Yuki,Kodama, Shintaro,Nomoto, Akihiro,Ueshima, Michio,Ogawa, Akiya
-
p. 11562 - 11571
(2019/10/03)
-
- Phosphine-Free Well-Defined Mn(I) Complex-Catalyzed Synthesis of Amine, Imine, and 2,3-Dihydro-1 H-perimidine via Hydrogen Autotransfer or Acceptorless Dehydrogenative Coupling of Amine and Alcohol
-
The application of nontoxic, earth-abundant transition metals in place of costly noble metals is a paramount goal in catalysis and is especially interesting if the air- and moisture-stable ligand scaffold is used. Herein, we report the synthesis of amines/imines directly from alcohol and amines via hydrogen autotransfer or acceptorless dehydrogenation catalyzed by well-defined phosphine-free Mn complexes. Both imines and amines can be obtained from the same set of alcohols and amines using the same catalyst, only by tuning the reaction conditions. The amount and nature of the base are found to be a highly important aspect for the observed selectivity. Both the primary and secondary amines have been employed as substrates for the N-alkylation reaction. As a highlight, we showed the chemoselective synthesis of resveratrol derivatives. Furthermore, the Mn-catalyzed dehydrogenative synthesis of structurally important 2,3-dihydro-1H-perimidines has also been demonstrated. Density functional theory calculations were also carried out to model the reaction path and to calculate the reaction profile.
- Das, Kalicharan,Mondal, Avijit,Pal, Debjyoti,Srivastava, Hemant Kumar,Srimani, Dipankar
-
supporting information
p. 1815 - 1825
(2019/04/30)
-
- Switching the N-Alkylation of Arylamines with Benzyl Alcohols to Imine Formation Enables the One-Pot Synthesis of Enantioenriched α-N-Alkylaminophosphonates
-
The selective N-alkylation of anilines with benzylic alcohols can be switched in favor of the dehydrogenative condensation process using the nitrile-ligated Kn?lker's complex by conducting the reaction either in a closed system under inert conditions, or in an open system in air. The selective formation of imines, containing reactive C=N bonds, provides an opportunity towards further functionalization. Indeed, a one-pot three-component condensation of alcohols, amines and phosphites, promoted by an iron-based Kn?lker-type complex in combination with a chiral BINOL-based phosphoric acid, provides access to enantioenriched α-N-alkylaminophosphonates.
- Hofmann, Natalie,Hultzsch, Kai C.
-
supporting information
p. 3105 - 3111
(2019/06/08)
-
- C-N Bond Formation Catalyzed by Ruthenium Nanoparticles Supported on N-Doped Carbon via Acceptorless Dehydrogenation to Secondary Amines, Imines, Benzimidazoles and Quinoxalines
-
Ruthenium nanoparticles (NPs) supported on N-doped carbon (Ru/N?C) were prepared by the pyrolysis of cis-Ru(phen)2Cl2 loaded onto carbon powder (VULCAN XC72R) at 800 °C. Ru/N?C NPs (0.2 mol% Ru) selectively catalyzed either acceptorless dehydrogenation coupling (ADC) or auto-transfer-hydrogen (ATH) reactions of amines with alcohols to imines and secondary amines. Such selectivity could be controlled by the choice of alkali metal ion associated with the base. Under similar catalytic conditions, the ADC cross-coupling of diamines with primary alcohols or diols afforded the corresponding benzimidazoles and quinoxalines in good to excellent yields. This catalytic system displayed good activity, recyclability, and wide applicability to a diverse range of substrates.
- Guo, Bin,Li, Hong-Xi,Zhang, Shi-Qi,Young, David James,Lang, Jian-Ping
-
p. 5627 - 5636
(2018/12/04)
-
- Grouping Effect of Single Nickel?N4 Sites in Nitrogen-Doped Carbon Boosts Hydrogen Transfer Coupling of Alcohols and Amines
-
As a new type of heterogeneous catalyst with “homogeneous-like” activity, single-site transition-metal materials are usually treated as integrated but separate active centers. A novel grouping effect is reported for single Ni?N4 sites in nitrogen-doped carbon (Ni/NC), where an effective ligand-stabilized polycondensation method endows Ni/NC nanocatalysts with a high content of single-site Ni up to 9.5 wt %. The enhanced electron density at each single Ni?N4 site promotes a highly efficient hydrogen transfer, which is exemplified by the coupling of benzyl alcohol and aniline into N-benzylaniline with a turnover frequency (TOF) value of 7.0 molN-benzylaniline molmetal?1 h?1; this TOF outpaces that of reported stable non-noble-metal-based catalysts by a factor of 2.
- Su, Hui,Gao, Peng,Wang, Meng-Ying,Zhai, Guang-Yao,Zhang, Jun-Jun,Zhao, Tian-Jian,Su, Juan,Antonietti, Markus,Li, Xin-Hao,Chen, Jie-Sheng
-
supporting information
p. 15194 - 15198
(2018/10/31)
-
- Remarkable difference between five- and six- number-membered ring transition states for intramolecular proton transfer in excited state
-
In this study, a range of organic dyes were prepared to investigate difference between five- and six- number-membered ring transition states for internal proton transfer in excited state. Different strength intramolecular hydrogen bond in the target dyes
- Qin, Xiaozhuan,Ding, Ge,Wang, Zhenqiang,Zhang, Shengtao,Li, Hongru,Luo, Ziping,Gao, Fang
-
-
- An Efficient Lewis Acid Catalyzed Povarov Reaction for the One-Pot Stereocontrolled Synthesis of Polyfunctionalized Tetrahydroquinolines
-
An easy and efficient synthetic methodology for the one-pot stereocontrolled synthesis of tetrahydroquinolines through Lewis acid activated Povarov reaction is described. The protocol takes advantage of the very cheap, easy to handle, and environmentally
- Cimarelli, Cristina,Bordi, Samuele,Piermattei, Pamela,Pellei, Maura,Del Bello, Fabio,Marcantoni, Enrico
-
p. 5387 - 5395
(2017/12/14)
-
- Design of recyclable TEMPO derivatives bearing an ionic liquid moiety and N, N-bidentate group for highly efficient Cu(i)-catalyzed conversion of alcohols into aldehydes and imines
-
Four different types of TEMPO derivatives incorporated with an ionic liquid moiety and N,N-bidentate coordination group (IL-TEMPO-N,N) were prepared. The CuBr/IL-TEMPO-N,N system showed high catalytic activity toward the synthesis of aldehydes and imines via the aerobic oxidation of alcohols in 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4). Both the Cu catalyst and IL-TEMPO-N,N co-catalyst in homogeneous catalytic systems could simultaneously be recovered from the products by extraction using Et2O. The remaining catalyst system in the ionic liquid phase could be reused for several cycles without obvious loss of catalytic activity. Protocols for highly efficient and recyclable aerobic oxidation of alcohols to aldehydes and imines were established.
- Guo, Bin,Xue, Jiang-Yan,Li, Hong-Xi,Tan, Da-Wei,Lang, Jian-Ping
-
p. 51687 - 51693
(2016/06/13)
-
- Reductive Umpolung of Carbonyl Derivatives with Visible-Light Photoredox Catalysis: Direct Access to Vicinal Diamines and Amino Alcohols via α-Amino Radicals and Ketyl Radicals
-
Visible-light-mediated photoredox-catalyzed aldimine-aniline and aldehyde-aniline couplings have been realized. The reductive single electron transfer (SET) umpolung of various carbonyl derivatives enabled the generation of intermediary ketyl and α-amino radical anions, which were utilized for the synthesis of unsymmetrically substituted 1,2-diamines and amino alcohols. Anilines can be coupled with aldimines or aldehydes in a visible-light-mediated photoredox-catalyzed process. Reductive single electron transfer (SET) umpolung of the carbonyl derivatives leads to the generation of intermediary ketyl and α-amino radical anions, which were used for the synthesis of unsymmetrically substituted 1,2-diamines and amino alcohols.
- Fava, Eleonora,Millet, Anthony,Nakajima, Masaki,Loescher, Sebastian,Rueping, Magnus
-
supporting information
p. 6776 - 6779
(2016/06/09)
-
- Metal-Organic Framework Nodes Support Single-Site Magnesium-Alkyl Catalysts for Hydroboration and Hydroamination Reactions
-
Here we present the first example of a single-site main group catalyst stabilized by a metal-organic framework (MOF) for organic transformations. The straightforward metalation of the secondary building units of a Zr-MOF with Me2Mg affords a hi
- Manna, Kuntal,Ji, Pengfei,Greene, Francis X.,Lin, Wenbin
-
supporting information
p. 7488 - 7491
(2016/07/06)
-
- Solvent-free synthesis method for preparing imine under catalysis of ligand-free ruthenium trichloride
-
The invention discloses a solvent-free synthesis method for preparing imine under catalysis of ligand-free ruthenium trichloride.Specifically, the method includes the following steps that under protection of inert gas, according to the molar ratio of nitrobenzene compounds, alcohol compounds, alkaline compounds and ruthenium trichloride being 1: (2-4): (1-2): (0.02-0.05), reactant is added into a reaction vessel provided with a stirring device, a stirring reaction is performed for 20-30 h at 100-150 DEG C, and imine compounds are obtained.Under the condition that no auxiliary ligands or solvents are added, RuCl3 is directly used as a catalyst for the first time.Besides, selective preparation of the imine compounds is achieved, the whole process is environmentally friendly, efficient and easy to operate, and the method is a good method for synthesizing the imine compounds.
- -
-
Paragraph 0032; 0033; 0034; 0035
(2016/10/10)
-
- Phosphine ligand-free RuCl3-catalyzed reductive N-alkylation of aryl nitro compounds
-
Without using any additional ligands, RuCl3efficiently catalyses the reductive N-alkylation of aryl nitro compounds with alcohols using bio-based glycerol as the hydrogen source and without the need for any added solvents. The reaction can be easily manipulated to produce either imines or secondary amines in high yields. RuCl3-catalyzed reductive N-alkylation of nitroarenes with alcohols affords the corresponding imine products in good to excellent yields. Under the same reaction conditions, the one-pot sequential reaction of nitroarenes with alcohols and glycerol also gives amines in higher yields.
- Tan, Da-Wei,Li, Hong-Xi,Young, David James,Lang, Jian-Ping
-
p. 4169 - 4176
(2016/07/06)
-
- Symbiotic Transition-Metal and Organocatalysis for Catalytic Ambient Amine Oxidation and Alkene Reduction Reactions
-
A new oxidation reaction based on two simple catalysts, namely, alloxan and a CuI salt, is highly effective for the aerobic oxidation and oxidative cross-coupling of amines. The reaction is operationally simple, reaction atmospheres enriched in dioxygen are obviated, and neither catalyst component requires prior synthesis. Mechanistic investigations have been performed and point towards a complex reaction manifold with evidence that supports a catalytic cycle that does not proceed through a quinone-imine step. Additionally, this dual catalyst system is efficient to effect diimide-mediated hydrogenation reactions of alkenes and alkynes, a transformation that has not been reported previously in the context of quinone catalyst systems.
- Murray, Alexander T.,King, Rose,Donnelly, Joseph V. G.,Dowley, Myles J. H.,Tuna, Floriana,Sells, Daniel,John, Matthew P.,Carbery, David R.
-
p. 510 - 514
(2016/02/20)
-
- Formation of Amides from Imines via Cyanide-Mediated Metal-Free Aerobic Oxidation
-
A new protocol for the direct formation of amides from imines derived from aromatic aldehydes via metal-free aerobic oxidation in the presence of cyanide is described. This protocol was applicable to various aldimines, and the desired amides were obtained in moderate to good yields. Mechanistic studies suggested that this aerobic oxidative amidation might proceed via the addition of cyanide to imines followed by proton transfer from carbon to nitrogen in the original imines, leading to carbanions of α-amino nitriles, which undergo subsequent oxidation with molecular oxygen in air to provide the desired amide compounds.
- Seo, Hong-Ahn,Cho, Yeon-Ho,Lee, Ye-Sol,Cheon, Cheol-Hong
-
p. 11993 - 11998
(2016/01/09)
-
- Base-mediated synthesis of imines and amines from N-phenylureas and alcohols
-
A new base-mediated protocol has been developed for the synthesis of imines and amines from N-phenylureas and alcohols under normal air. From the synthetic point of view, the protocol can be considered as an efficient alternative to conventional methods for the synthesis of imines and amines in moderate to excellent yields.Georg Thieme Verlag Stuttgart. New York.
- Yadav, Dilip Kumar T.,Bhanage, Bhalchandra M.
-
supporting information
p. 1611 - 1615
(2014/07/08)
-
- Selective aerobic oxidation of alcohols to aldehydes, carboxylic acids, and imines catalyzed by a Ag-NHC complex
-
Silver NHC catalysts have been developed for the selective oxidation of alcohols to aldehydes or carboxylic acids in the presence of BnMe3NOH or KOH under dry air. The aerobic oxidation conditions are mild, and the yield is excellent. Further tandem catalysis enables the one-pot synthesis of imines in excellent yield. Only 0.1 mol % of the catalyst is required.
- Han, Lei,Xing, Ping,Jiang, Biao
-
supporting information
p. 3428 - 3431
(2014/07/21)
-
- Magnesium catalysis of imine hydroboration
-
The β-diketiminato magnesium alkyl complex [LMgnBu] (L=CH{CMe(NDipp)}2, Dipp=diisopropylphenyl) is shown to be a highly effective precatalyst for the hydroboration of alkyl and aryl substituted aldimines and ketimines with pinacol borane (HBpin). Catalysis is proposed to occur through a sequence of Mg-N/B-H metathesis and rate-determining Mg-H/N=C insertion steps, a proposal strongly supported by stoichiometric studies and kinetic analysis. The reactions are observed to proceed through the intermediacy of well-defined magnesium amides, two examples of which have been isolated and structurally characterized. Mechanistic investigations suggest that the catalytic rate-determining process occurs at an isolated magnesium center and requires the presence of two molecules of the imine substrate for effective turnover. This latter observation is rationalized as a requirement for the secondary substrate molecule to displace HBpin from the coordination sphere of the catalytic magnesium center.
- Arrowsmith, Merle,Hill, Michael S.,Kociok-Koehn, Gabriele
-
supporting information
p. 2776 - 2783
(2013/03/14)
-
- Highly active and selective synthesis of imines from alcohols and amines or nitroarenes catalyzed by Pd/DNA in water with dehydrogenation
-
A direct imination was developed from alcohols and amines under catalysis of Pd/DNA by dehydrogenation without additional oxidant, affording the corresponding imines in moderate to good yields with excellent chemoselectivity. By virtue of the liberated molecular hydrogen, the nitroarenes could also be deoxidized in situ into amines and a one-pot tandem synthesis of imines was achieved from nitroarenes. This heterogeneous catalyst can be recovered and reused at least five times by taking advantage of its water-soluble reversibility. All these conformations were performed smoothly in water under mild conditions, and an atom economical and environmentally benign synthesis was embodied in this imination.
- Tang, Lin,Sun, Huayin,Li, Yunfeng,Zha, Zhenggen,Wang, Zhiyong
-
p. 3423 - 3428
(2013/01/16)
-
- Proline triflate catalysed Diels-Alder reaction in the synthesis of tetrahydroquinoline derivatives
-
Proline triflate was found to catalyse efficiently the one-pot synthesis of 2H-pyranotetrahydroquinolines from aryl imines, and 3,4-dihydro-2H-pyran with high stereoselectivity. The aryl imines were formed in situ from aromatic amines and arylaldehydes.
- Li, Jianjun,Li, Jia,Su, Weike
-
experimental part
p. 499 - 504
(2010/01/16)
-
- A new pyridyl bis(oxazoline) ligand prepared from D-glucosamine for asymmetric alkynylation of imines
-
A new carbohydrate-based pyridyl bis(oxazoline) has been prepared from D-glucosamine via simple steps. With this ligand enantioselectivities up to 99% were achieved in copper(I)-catalysed alkynylations of imines.
- Irmaka, Mustafa,Boysena, Mike M. K.
-
experimental part
p. 403 - 405
(2009/04/06)
-
- A convenient approach to δ-amino-β-ketoesters by vinylogous Mannich reaction of masked acetoacetates
-
SiCl4 is an efficient and selective catalyst for the vinylogous Mannich reaction of linear and cyclic synthetic equivalents of acetoacetate dianion, leading to δ-amino-β-ketoesters in moderate to high yields and complete γ-selectivity; anti-diastereoselectivity was observed by using a γ-methyl-substituted cyclic silyloxydiene.
- Villano, Rosaria,Acocella, Maria Rosaria,Massa, Antonio,Palombi, Laura,Scettri, Arrigo
-
p. 12317 - 12323
(2008/03/13)
-
- Imino Diels-Alder reactions: an efficient one-pot synthesis of pyrano and furanoquinoline derivatives catalyzed by SbCl3
-
Antimony trichloride (SbCl3) was found to be an efficient catalyst for the inverse electron demand imino Diels-Alder reactions of in situ generated N-benzylidenes with 3,4-dihydro-2H-pyran and 2,3-dihydrofuran to afford pyrano and furano[3,2-c]quinolines in excellent yields.
- Maiti, Gourhari,Kundu, Pradip
-
p. 5733 - 5736
(2007/10/03)
-
- Gallium metal mediated allylation of carbonyl compounds and imines under solvent-free conditions
-
Gallium metal is effective in mediating the allylation of various carbonyl compounds and imines under solvent-free conditions, with the application of sonic energy, affording the corresponding homoallylic alcohols and amines. The imines themselves were al
- Andrews, Philip C.,Peatt, Anna C.,Raston, Colin L.
-
p. 243 - 248
(2007/10/03)
-
- Rearrangements in the Molecular Ions of Some ortho-Substituted Schiff Bases
-
Under electron ionization conditions, the ortho-substituted Schiff bases N-benzylidene-o-toluidine (1a), N-(o-methylbenzylidene)aniline (1b), N-salicylideneaniline (1c) and N-(o-methoxybenzylidene)aniline (1d) give fragment ions which have been shown by collision-activated mass-analysed ion kinetic energy spectra to have the structure of the protonated molecular ions of indole (2), benzofuran (3), and 1,2-benzisoxazole (4). The molecular ion of N-(o-methylbenzylidene)-o-toluidine (1f) gives as fragment ions not only the protonated molecular ion (2) of indole and the tropylium ion but also the molecular ion of anthracene. Attempts to find supporting evidence for a mechanism for this rearrangement by deuterium labelling of a methyl group in (1b), such as (1g), have been unsuccessful.
- Blumenthal, Thomas,Dosen, Miroslav,Gillis, Richard G.,Porter, Quentin N.
-
p. 895 - 901
(2007/10/02)
-
- Electrosynthesis of N-Substituted DL-Arylglycineesters and 1,2-Diarylamino-1,2-diarylethanes by Cathodic Reduction of Azomethines in the Presence of Carbon Dioxide
-
The electroreduction of the N-arylidene-arylamines 1-12 in CO2-saturated solvents of low proton availability as DMF at markedly more positive potentials than carbon dioxide end up in carboxylating the C-atom and hydrogenating the nitrogen of the C=N-double bond.The resulting N-arylsubstituted DL-arylglycines and traces of carbamates may be isolated as esters, adding ethylchloride during the electrolysis.A competing pathway of the electrocarboxylation is the C-C-hydrodimerisation and the hydrogenation of the C=N-double bond, whose importance increases with the water content of the solvent.Based on cyclic-voltametric evidence and product analysis the mechanism of the reductive electrocarboxylation reaction is discussed in terms of nucleophilic attack of the azomethine anion radical on a proton or CO2.
- Hess, U.,Thiele, R.
-
p. 385 - 399
(2007/10/02)
-