- Redox properties of CeO2at low temperature: The direct synthesis of imines from alcohol and amine
-
We disclosed the redox properties of CeO2 in organic reactions at low temperature of 303 K. CeO2 works as the most effective heterogeneous catalyst for imine formation from benzyl alcohol and aniline at 303 K among various metal oxides and showed more than 38-fold higher activity than other simple metal oxides. CeO2 is applicable to the reaction of various alcohols and amines and gives high yields (80-98%) and high selectivities (89- > 99%). Kinetic measurements, MS, and FTIR analyses demonstrated that the high activity of CeO2 is a result of reactive oxygen species at the redox sites on CeO2. This discovery can help to create a new field in metal oxide catalysis.
- Tamura, Masazumi,Tomishige, Keiichi
-
-
Read Online
- 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
-
-
Read Online
- One-pot imine synthesis from methylarenes and anilines under air over heterogeneous Cu oxide-modified CeO2catalyst
-
Cu oxide-modified CeO2 (CuOx-CeO2) with 2 wtpercent Cu loading amount was the most effective and reusable heterogeneous catalyst for selective one-pot imine synthesis from methylarenes and anilines via direct oxidation of the sp3 C-H bond in the methylare
- Tamura, Masazumi,Li, Yingai,Tomishige, Keiichi
-
-
Read Online
- A mild and efficient synthesis of substituted quinolines via a cross-dehydrogenative coupling of (Bio)available alcohols and aminoarenes
-
A ruthenium-catalysed dehydrogenative cross-coupling of primary alcohols and imines in the presence of TFA provided a library of differently substituted quinolines. Imines can be prepared in situ from various anilines and several benzyl alcohols using a ruthenium-catalysed hydrogen-transfer procedure. Without changing the catalyst, quinolines can be obtained in moderate to good yields by adding various primary alcohols in the presence of TFA (30 mol%) via a "telescopic" protocol. The use of alcohols, the absence of strong oxidants and the diversity of potential starting materials make this modern version of the Skraup reaction superior to most of the conventional quinoline syntheses.
- Mura, Manuel G.,Rajam?ki, Suvi,De Luca, Lidia,Cini, Elena,Porcheddu, Andrea
-
-
Read Online
- Unlocking the direct photocatalytic difluoromethylation of CN bonds
-
The current study presents a direct CF2H radical addition to CN bonds predicated on the photocatalytic activation of commercially available zinc difluoromethanesulfinate. The mild conditions in place lead to impressive structural diversity, as quinoxalinones and dibenzazepines, among others, are successfully functionalized.
- Alemán, José,Garrido-Castro, Alberto F.,Gini, Andrea,Maestro, M. Carmen
-
-
Read Online
- Amorphous Fe2O3 improved [O] transfer cycle of Ce4+/Ce3+ in CeO2 for atom economy synthesis of imines at low temperature
-
CeO2 based catalysts have been investigated in various catalytic reactions due to its unique reversible Ce3+/Ce4+ redox pair and physicochemical property, but its poor cycle efficiency and low reservoir limit its wide application in the fine chemicals industry. In this work, a novel amorphous Fe2O3 modified CeO2 catalytic system was developed by a facile co-precipitation method. The as-prepared samples were characterized in detail, and were employed for catalyzing the one-pot synthesis of imine from benzyl alcohol and aniline under air atmosphere at low temperature. The as-prepared sample with molar ratio of Fe:Ce = 8:2 dried at 100 °C (named Fe8Ce2-100) exhibited superhigh activity for atom economy synthesis of imine, which was much higher than the reported CeO2 catalyst, even higher than some noble metal catalysts. It is worth noting that pure amorphous Fe2O3-100 could not catalyze this reaction at all, and both pure CeO2-100 and the mechanical mixed sample with the same molar ratio of Fe:Ce exhibited much more inferior catalytic activity than Fe8Ce2-100. Combining characterization results and the catalytic activities of different catalysts at various reaction conditions, the enhanced catalytic activity of Fe8Ce2-100 could be ascribed to the novel synergistic effect between CeO2 and amorphous Fe2O3. Amorphous Fe2O3 plays the role of engine to greatly improve the [O] transfer cycle of Ce4+/Ce3+, as well as enhances the redox and amphoteric properties of the catalysts. This work firstly determines amorphous Fe2O3 can participate and facilitate the catalytic cycle for organic reaction, and may provide a significant strategy for designing polymetallic oxide catalyst towards organic aerobic transformation.
- Qin, Jiaheng,Long, Yu,Wu, Wei,Zhang, Wei,Gao, Zekun,Ma, Jiantai
-
-
Read Online
- A Route to Polysubstituted Aziridines from Carbenes and Imines through a Nondiazo Approach
-
An efficient method for the synthesis of polysubstituted aziridines utilizing enynones and imines is described. This transformation is achieved through the reaction of imines with donor/donor carbene intermediates, which were generated in situ from the cyclization of enynones. Furthermore, the resulted aziridines were good 1,3-dipoles, which could be efficiently trapped by dipolarophiles to give five-membered heterocycles. The obvious advantages of wide substrate scopes, mild reaction conditions, and high atom efficiency make this system highly appealing for construction of polysubstituted aziridines, 2,5-dihydropyroles, and 1,2,4-triazolidines.
- Luo, Hejiang,Chen, Kai,Jiang, Huanfeng,Zhu, Shifa
-
-
Read Online
- Uniform Cu/chitosan beads as a green and reusable catalyst for facile synthesis of iminesviaoxidative coupling reaction
-
A nonprecious metal and biopolymer-based catalyst, Cu/chitosan beads, has been successfully prepared by using a software-controlled flow system. Uniform, spherical Cu/chitosan beads can be obtained with diameters in millimeter-scale and narrow size distribution (0.78 ± 0.04 mm). The size and morphology of the Cu/chitosan beads are reproducible due to high precision of the flow rate. In addition, the application of the Cu/chitosan beads as a green and reusable catalyst has been demonstrated using a convenient and efficient protocol for the direct synthesis of iminesviathe oxidative self- and cross-coupling of amines (24 examples) with moderate to excellent yields. Importantly, the beads are stable and could be reused more than ten times without loss of the catalytic performance. Furthermore, because of the bead morphology, the Cu/chitosan catalyst has greatly simplified recycling and workup procedures.
- Bunchuay, Thanthapatra,Chantiwas, Rattikan,Chutimasakul, Threeraphat,Intanin, Apichai,Na Nakhonpanom, Pakamon,Tantirungrotechai, Jonggol,Tirdtrakool, Warinda
-
-
Read Online
- Tuning effect of amorphous Fe2O3on Mn3O4for efficient atom-economic synthesis of imines at low temperature: Improving [O] transfer cycle of Mn3+/Mn2+in Mn3O4
-
A facile and scaled-up synthesis route to efficient and environment-friendly metal oxide catalysts with desirable properties is of great practical importance, owing to their excellent performance as heterogeneous catalysts in organic synthesis. Herein, a novel amorphous Fe2O3 modified Mn3O4 catalyst (Fe5Mn5-100) has been prepared by adopting a simple co-precipitation method following low temperature baking. Fe5Mn5-100 showed exceptionally high catalytic activity for the atom-economic production of imine from benzyl alcohol with aniline, giving a 98% imine yield at 60 °C in only 3 h, which is higher than all of the reported non-noble and noble metal catalysts. Importantly, Fe5Mn5-100 could still exhibit extraordinary catalytic performance on a large-scale reaction without any solvent, including the frequently used toxic mesitylene, xylene or toluene. Interestingly, the amorphous Fe2O3-100 provided no catalytic activity, and pure Mn3O4-100 showed very inferior catalytic activity towards this reaction. Further detailed characterizations and experimental results revealed that amorphous Fe2O3 plays an important role in expediting the [O] transfer cycle of Mn3+/Mn2+ in Mn3O4, and enhances the oxidation ability and acidity of Fe5Mn5-100. This discovery would provide a new avenue for the atom-economic and environment-friendly industrial synthesis of imine. This journal is
- Cao, Xiao,Gou, Galian,Long, Yu,Luo, Shicheng,Luo, Yutong,Ma, Jiantai,Qin, Jiaheng,Wang, Kaizhi,Wu, Wei
-
-
Read Online
- 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
-
-
Read Online
- A ruthenium-based catalytic system for a mild borrowing-hydrogen process
-
The alkylation of arylamines using stoichiometric amounts of aliphatic and benzylic alcohols in the presence of tBuOK was carried out at 55 °C using a low catalyst loading of [Ru(cod)-Cl2]n/PTA (1,3,5-triaza-7-phosphaadamantane). The overall borrowing-hydrogen process does not require a controlled nitrogen atmosphere, and it could also be carried out at room temperature using higher loading of base. A wide range of substrates can be used in this transformation, and it has a good tolerance of different substituents. This catalytic system proved also to be efficient for other hydrogen-transfer reactions such as a tandem oxidation/C-C coupling between 1-phenylethanol and primary alcohols.
- Jumde, Varsha R.,Gonsalvi, Luca,Guerriero, Antonella,Peruzzini, Maurizio,Taddei, Maurizio
-
-
Read Online
- Manganese-Catalyzed and Base-Switchable Synthesis of Amines or Imines via Borrowing Hydrogen or Dehydrogenative Condensation
-
The use of earth-abundant transition metals as a noble metal replacement in catalysis is especially interesting if different catalytic reactivity is observed. We report, here, on the selective manganese-catalyzed base-switchable synthesis of N-alkylated amines or imines. In both reactions, borrowing hydrogen/hydrogen autotransfer (N-alkyl amine formation) or dehydrogenative condensation (imine formation), we start from the same amines and alcohols and use the same Mn precatalyst. The key is the presence of a potassium base to prefer N-alkylation and a sodium base to permit imine formation. Both bases react with the manganese hydride via deprotonation. The potassium manganate hydride reacts about 40 times faster with an imine to give the corresponding amine than the sodium manganate hydride. The selectivity seems unique for manganese complexes. We observe a broad scope with a complete product overlap, all amine alcohol combinations can be converted into an N-alkyl amine or an imine, and a good functional group tolerance.
- Fertig, Robin,Irrgang, Torsten,Freitag, Frederik,Zander, Judith,Kempe, Rhett
-
-
Read Online
- Photocatalytic one-pot multidirectional N-alkylation over Pt/D-TiO2/Ti3C2: Ti3C2-based short-range directional charge transmission
-
Visible-light-induced one-pot, multistep, and chemoselectivity adjustable reactions highlight the economical, sustainable, and green process. Herein, we report Pt nanoparticles dispersed on S and N co-doped titanium dioxide/titanium carbide (MXene) (3%Pt/
- Jiang, Heyan,Sheng, Meilin,Li, Yue,Kong, Shuzhen,Bian, Fengxia
-
-
- Ionic-Liquid-Catalyzed Synthesis of Imines, Benzimidazoles, Benzothiazoles, Quinoxalines and Quinolines through C?N, C?S, and C?C Bond Formation
-
We report the tetramethyl ammonium hydroxide catalyzed oxidative coupling of amines and alcohols for the synthesis of imines under metal-free conditions by utilizing oxygen from air as the terminal oxidant. Under the same conditions, with ortho-phenylene diamines and 2-aminobenzenethiols the corresponding benzimidazoles and benzothiazoles were obtained. Quinoxalines were obtained from ortho-phenylene diamines and 1-phenylethane-1,2-diol, the conditions were then extended to the synthesis of quinoline building blocks by reaction of 2-amino benzyl alcohols either with 1-phenylethan-1-ol or acetophenone derivatives. The formation of C?N, C?S and C?C bonds was achieved under metal-free conditions. A broad range of amines (aromatic, aliphatic, cyclic and heteroaromatic) as well as benzylic alcohols including heteroaryl alcohols reacted smoothly and provided the desired products. The mild reaction conditions, commercially available catalyst, metal-free, good functional-group tolerance, broad range of products (imines, benzimidazoles, benzothiazoles, quinoxalines and quinolines) and applicability at gram scale reactions are the advantages of the present strategy.
- Adimurthy, Subbarayappa,Badhani, Gaurav,Joshi, Abhisek
-
p. 6705 - 6716
(2021/12/31)
-
- 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
-
-
- Switchable Imine and Amine Synthesis Catalyzed by a Well-Defined Cobalt Complex
-
Switchable imine and amine synthesis catalyzed by a tripodal ligand-supported well-defined cobalt complex is presented herein. A large variety of primary alcohols and amines were selectively converted to imines or amines in good to excellent yields. It is discovered that the base plays a crucial role on the selectivity. A catalytic amount of base leads to the imine formation, while an excess loading of base results in the amine product. This strategy on product selectivity also strongly depends on the organometallic catalysts in use. We expect that the present study could provide useful insights toward selective organic synthesis and catalyst design.
- Paudel, Keshav,Xu, Shi,Hietsoi, Oleksandr,Pandey, Bedraj,Onuh, Chuka,Ding, Keying
-
supporting information
p. 418 - 426
(2021/02/01)
-
- 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)
-
- Rhodium catalyzed multicomponent dehydrogenative annulation: one-step construction of isoindole derivatives
-
A strategy for one-pot synthesis of isoindoles is describedviaa catalytic multicomponent dehydrogenative annulation of diarylimines, vinyl ketones and simple amines. In the presence of a rhodium catalyst and Cu oxidant, four C-H and two N-H bonds are activated along with the formation of one new C-C and two new C-N bonds, leading to a series of isoindole derivatives in good to very high isolated yields.
- Cheng, Biao,Lyu, Hairong,Quan, Yangjian,Xie, Zuowei
-
supporting information
p. 7930 - 7933
(2021/08/17)
-
- 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)
-
- Method for synthesizing imine by catalyzing alcohol-amine through NNN cobalt complex
-
The invention discloses a method for synthesizing imine by catalyzing alcohol-amine through an NNN cobalt complex. The method comprises the following steps: in a nitrogen atmosphere and at the temperature of 75-85 DEG C, taking an organic solvent as a solvent, taking an NNN cobalt complex (LCoCl2) as a catalyst under an alkaline condition, and reacting arylamine with aryl methanol for 40-55 hoursto obtain imine. The preparation method has the characteristics of high yield, few by-products, environmental friendliness and the like and has a wide application prospect.
- -
-
Paragraph 0062-0065
(2020/07/02)
-
- Insight into Ce Doping Induced Oxygen Vacancies over Ce-Doped Mno2 Catalysts for Imine Synthesis
-
The pursuit of modern sustainable chemistry has stimulated the development of innovative catalytic processes that enable chemical transformations to be performed under mild and clean conditions with high efficiency. Here, an amorphous sheet-like MnO2 (Ce-doped MnO2: CMBO) was obtained after Ce doping, which exhibits excellent catalytic performance for the oxidation coupling of alcohol and aniline. Conversion of 99% and a selectivity of 99% could be achieved within 6 h at 60 oC under air atmosphere, and the formation rate of target product was up to 30.2 μmol·h–1·m–2. Based on a series of characterizations, it was found that the doping of Ce into the MnO2 could increase the concentration of the oxygen vacancies, thus forming abundant active surface oxygen species and favoring the mobility of lattice oxygen, which are the main reasons for the greatly enhanced catalytic performance of CMBO. This work indicates that increasing oxygen vacancy by element doping may serve as a facile and efficient way to enhance catalytic performance of transition metal oxide.
- Shen, Haidong,Bu, Jun,Wang, Wenbin,Wu, Chen,Cao, Yueling,Zhang, Baoliang,Zhang, Qiuyu,Zhang, Hepeng
-
supporting information
p. 1353 - 1359
(2020/08/25)
-
- Functionalization of activated methylene C-H bonds with nitroarenes and sulfur for the synthesis of thioamides
-
We report a method to obtain arylthioamides by the functionalization of sp3 C-H bonds in phenylacetic acids and benzyl alcohols. Reactions proceeded without the use of any solvents and were compatible with many functionalities and heterocycles. These conditions allow for a rapid synthesis of thioamides from simple, commercial substrates.
- Do, Nhan T.,Tran, Khoa M.,Phan, Hao T.,To, Tuong A.,Nguyen, Tung T.,Phan, Nam T. S.
-
p. 8987 - 8991
(2019/10/28)
-
- Bi-functional catalyst of porous N-doped carbon with bimetallic FeCu for solvent-free resultant imines and hydrogenation of nitroarenes
-
The efficient and stable catalyst applied to the transformation of amines into the corresponding imines and hydrogenation of nitroarenes under mild reaction conditions is reported. The catalytic performance of porous N-doped carbon with FeCu (FeCu@NPC) catalyst are tested by aromatic alcohol-based N-alkylated of amines with solvent-free and hydrogenation of nitroarenes via N2H4·H2O. The results proved that the yield of these two reactions are all over 99.9% under optimum condition. Moreover, the synergistic effect of the catalyst for N-alkylated reaction was investigated through the kinetic study. The catalyst can be easily separated from reaction system by an external magnetism, and can be recycled and reutilized for at least 4 runs with conversions are all over 75%. The study of the catalyst indicated that it was suitable for the reactions in industry. Hence, the catalysis process by the inexpensive metals-based catalyst is green and sustainable.
- Wang, Kaizhi,Gao, Wenbing,Jiang, Pengbo,Lan, Kai,Yang, Ming,Huang, Xiaokang,Ma, Lei,Niu, Fang,Li, Rong
-
-
- 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)
-
- Method for preparing imine by utilizing copper catalyst to catalyze cross coupling of amine and alcohol
-
The invention discloses a method for preparing imine by utilizing a copper catalyst to catalyze cross coupling of amine and alcohol. The method comprises the following steps: under the condition of nooxidant, adopting Cu/Al2O3 as a catalyst to catalyze the cross coupling of the amine and the alcohol so as to prepare the imine. The method disclosed by the invention has beneficial effects that thereaction system is simple, cocatalysts such as organic ligand, alkaline, and free radical of nitroxide do not need to be added, and simultaneously under the condition of no oxidant, the method utilizes Cu/Al2O3 to catalyze cross coupling of the amine and the alcohol so as to prepare the imine; the problem that the imine is easily peroxidated can be effectively solved; in addition, the catalyst Cu/Al2O3 used by the method is simple in preparation, is highly-effective and stable and is low in price.
- -
-
Paragraph 0036; 0037; 0039
(2019/02/04)
-
- H2-Generation from Alcohols by the MOF-Based Noble Metal-Free Photocatalyst Ni/CdS/TiO2@MIL-101
-
The synthesis of important classes of chemical compounds from alcohols helps to conserve Earth's fossil carbon resources, since alcohols can be obtained from indigestible and abundantly available biomass. The utilisation of visible light for the activation of alcohols permits alcohol-based C-N and C-C bond formation under mild conditions inaccessible with thermally operating hydrogen liberation catalysts. Herein, we report on a noble metal-free photocatalyst able to split alcohols into hydrogen and carbonyl compounds under inert gas atmosphere without the requirement of electron donors, additives, or aqueous reaction media. The reusable photocatalyst mediates C-N multiple bond formation using the oxidation of alcohols and subsequent coupling with amines. The photocatalyst consists of a CdS/TiO2 heterojunction decorated with co-catalytic Ni nanoparticles and is prepared on size-optimised colloidal metal-organic framework (MOF) crystallites.
- Tilgner, Dominic,Klarner, Mara,Hammon, Sebastian,Friedrich, Martin,Verch, Andreas,De Jonge, Niels,Kümmel, Stephan,Kempe, Rhett
-
p. 842 - 847
(2019/08/26)
-
- PdAu@MIL-100(Fe) cooperatively catalyze tandem reactions between amines and alcohols for efficient N-alkyl amines syntheses under visible light
-
PdAu@MIL-100(Fe), with PdAu alloy nanoparticles of ca. 1.7 nm encapsulated inside MIL-100(Fe) cavities, were prepared via a double-solvent impregnation followed by photoreduction. As compared with bare Pd@MIL-100(Fe), bimetallic PdAu@MIL-100(Fe) showed superior activities for the tandem reactions between amines and alcohols to produce N-alkyl amines under visible-light irradiation, ascribed to the promoting effect of metallic Au in the photocatalytic alcohol-to-aldehyde dehydrogenation. A Pd/Au ratio dependent N-alkylation activity was observed over PdAu@MIL-100(Fe), implying the possibility of synchronizing the reaction rates of two consecutive steps in the N-alkylation reaction, i.e., photocatalytic alcohol-to-aldehyde dehydrogenation and imines hydrogenation, to optimize the whole reaction. This study provides a highly efficient and stable catalytic system for the realization of alkylation of amines via a successful coupling of MOF-based photocatalysis and metal nanoparticle-based hydrogenation. This work also demonstrates that the reaction rates of different catalytic steps in a cascade/tandem reaction can be synchronized for an efficient overall reaction via a rational design of the multifunctional catalysts.
- Wang, Dengke,Pan, Yating,Xu, Lizhi,Li, Zhaohui
-
p. 248 - 254
(2018/04/02)
-
- Manganese catalyzed reductive amination of aldehydes using hydrogen as a reductant
-
A one-pot two-step procedure was developed for the alkylation of amines via reductive amination of aldehydes using molecular dihydrogen as a reductant in the presence of a manganese pyridinyl-phosphine complex as a pre-catalyst. After the initial condensation step, the reduction of imines formed in situ is performed under mild conditions (50-100 °C) with 2 mol% of catalyst and 5 mol% of tBuOK under 50 bar of hydrogen. Excellent yields (>90%) were obtained for a large combination of aldehydes and amines (40 examples), including aliphatic aldehydes and amino-alcohols.
- Wei, Duo,Bruneau-Voisine, Antoine,Valyaev, Dmitry A.,Lugan, No?l,Sortais, Jean-Baptiste
-
supporting information
p. 4302 - 4305
(2018/05/03)
-
- A novel straightforward synthesis of α-aminophosphonates: one-pot three-component condensation of alcohols, amines, and diethylphosphite in the presence of CuO@Fe3O4 nanoparticles as a catalyst
-
We report here a novel and straightforward synthesis method for the preparation of α-aminophosphonates in relatively good yield. The method involves the one-pot three-component condensation of alcohols, amines, and diethylphosphite in the presence of CuO@Fe3O4 nanoparticles as a recyclable catalyst. CuO@Fe3O4 nanoparticles were prepared and their structures were confirmed by the FT-IR, TGA, VSM, TEM and X-ray diffraction patterns analyses.
- Kaboudin, Babak,Kazemi, Foad,Hosseini, Narges Kadkhoda
-
p. 4475 - 4486
(2017/07/22)
-
- Coupling MOF-based photocatalysis with Pd catalysis over Pd@MIL-100(Fe) for efficient N-alkylation of amines with alcohols under visible light
-
Pd nanoparticles with an average size of 1.7 nm confined inside a MIL-100(Fe) cavity (Pd@MIL-100(Fe)) were prepared via double-solvent impregnation combined with a photoreduction process. Due to efficient coupling of photocatalytic dehydrogenation and Pd-based hydrogenation, the resultant Pd@MIL-100(Fe) showed significantly superior performance in light-induced N-alkylation of amines with alcohols over Pd/MIL-100(Fe), in which larger Pd nanoparticles (6–12 nm) deposited on the external surface of MIL-100(Fe) were prepared via a conventional single-solvent impregnation followed by a similar photoreduction process. Kinetic studies and controlled experiments revealed that the whole N-alkylation reaction is limited by the photocatalytic alcohol-to-aldehyde dehydrogenation reaction. This is the first demonstration of light-induced N-alkylation of amines by alcohols over M/MOFs nanocomposites and also highlights the great potential of using M/MOFs nanocomposites as multifunctional catalysts for light-induced organic syntheses.
- Wang, Dengke,Li, Zhaohui
-
p. 151 - 157
(2018/03/29)
-
- Load manganese oxidizing catalytic chipboard spreading method for one-step synthesis of imines
-
The invention belongs to the technical fields of chemistry and chemical engineering, and concretely relates to a method for one step synthesis of imine through catalyzing alcohol and amine by supported manganese oxide. A reaction of alcohol and amine is carried out in a solvent or solvent-free state at 60-90DEG C for 6-48h with the supported manganese oxide as a catalyst and molecular oxygen or air as an antioxidant to realize one step synthesis of a corresponding imine compound. The valence of manganese in the catalyst is +2, +3 or +4, the general formula of the catalyst is MnOx, and a carrier is hydroxyapatite (Ca10(PO4)6(OH)2). The catalyst still has very good activity and selectivity after the catalyst is reused at least 9 times. The catalyst used in the method has the characteristics of simple preparation, cheapness, high reaction selectivity and environmental protection.
- -
-
Paragraph 0024; 0025
(2017/02/02)
-
- 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)
-
- An efficient alkynylation of 4-thiazolidinone with terminal alkyne under C-H functionalisation
-
A method of palladium catalysed efficient alkynylation through the cross coupling reaction of terminal alkynes with the slightly more acidic C-H bonds of 4-thiazolidinone has been developed. This method allows the direct introduction of an ethynyl group into the 4-thiazolidinone moiety. Mild reaction conditions involving aerial oxidation and one pot synthesis make this reaction more efficient for the formation of sp3(C)-sp(C) bond.
- Shaikh, Mohammed Umar M.,Mudaliar, Sulochana S.,Chikhalia, Kishor H.
-
p. 50780 - 50785
(2016/06/09)
-
- Heterogeneous Catalytic Reductive Amination of Carbonyl Compounds with Ni-Al Alloy in Water as Solvent and Hydrogen Source
-
The heterogeneous catalytic reductive amination of carbonyl compounds has been achieved by reactions of ammonium hydroxide and various amines with ketones and aldehydes. The process is based on the application of Raney type Ni-Al alloy in an aqueous medium. The reaction of the carbonyl compounds with the amine provided the corresponding Schiff bases that immediately underwent a reduction to provide primary and secondary amines as products. The controlled reaction of the Al content of the alloy with the solvent water generates hydrogen, and the in situ formed Raney Ni serves as a hydrogenation catalyst. The method is a simple and efficient way of preparing a broad variety of primary and secondary amines.
- Sch?fer, Christian,Ni?anci, Bilal,Bere, Matthew P.,Da?tan, Arif,T?r?k, Béla
-
p. 3127 - 3133
(2016/09/09)
-
- Copper(I)-Catalyzed regioselective amination of N -aryl imines using TMSN3 and TBHP: A route to substituted benzimidazoles
-
A novel and efficient copper-catalyzed amination of N-aryl imines is described. This one-pot, multicomponent reaction, in which imine acts as a directing group by chelating to the metal center, affords a potential route for the transformation of the commercial aryl amines, aldehydes, and azides into valuable benzimidazole structural units with wide substrate scope and diversity. The synthetic and mechanistic aspects are presented.
- Mahesh, Devulapally,Sadhu, Pradeep,Punniyamurthy, Tharmalingam
-
p. 1644 - 1650
(2015/02/19)
-
- First efficient two-step/one-pot zirconium (IV)isopropoxide-mediated reductive amination of carbonyl compounds
-
An efficient method for the synthesis of various primary and secondary amines through a zirconium(IV) isopropoxide-mediated reductive amination reaction of aldehydes and ketones is reported. A series of different aldehydes, ketones and amines were used leading to the expected amino products in moderate to excellent yields. The mechanistic rationale of this reaction has been postulated through the formation of a transient imine species and a diastereoselective version using (R)-phenylethylamine as chiral inducer led to the expected products in moderate to excellent yields and with diastereoselectivities up to 100%.
- Pieri, Cyril,Brunel, Jean Michel
-
p. 448 - 456
(2015/06/22)
-
- 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)
-
- Direct imine formation by oxidative coupling of alcohols and amines using supported manganese oxides under an air atmosphere
-
Manganese oxides loaded on various supports have been prepared and studied for the direct imine formation by oxidative coupling of alcohols and amines. Among the catalysts, hydroxyapatite supported manganese oxides (MnO x/HAP) show the best activity and selectivity for this reaction in the absence of an additional base using air as the environmentally benign terminal oxidant. NH3-/CO2-TPD results show that the amphoteric properties of MnOx/HAP are crucial for this reaction to obtain a satisfactory yield. Various aromatic alcohols and amines are smoothly transformed into the corresponding imines in good to excellent yields. The catalyst is reusable and gives 98% yield of the product in all 9 reuse tests. Compared with the fresh catalyst, the XRD and SEM of the reactivated MnO x/HAP after nine reactions do not show any obvious change. This journal is the Partner Organisations 2014.
- Chen, Bo,Li, Jun,Dai, Wen,Wang, Lianyue,Gao, Shuang
-
p. 3328 - 3334
(2014/06/10)
-
- Silver-catalyzed alkyne activation: The surprising ligand effect
-
An unexpected ligand effect was discovered in the silver(I)-catalyzed alkyne activation. For both aldehyde-alkyne-amine (A3) condensation and intermolecular alkyne hydroamination, the type B complex (P:Ag=1:1) effectively promoted the reaction, while no reaction occurred with either no ligand or excess ligands under the identical conditions.
- Su, Yijin,Lu, Mei,Dong, Boliang,Chen, Hao,Shi, Xiaodong
-
supporting information
p. 692 - 696
(2014/04/03)
-
- Heteroatom-free arene-cobalt and arene-iron catalysts for hydrogenations
-
75 years after the discovery of hydroformylation, cobalt catalysts are now undergoing a renaissance in hydrogenation reactions. We have evaluated arene metalates in which the low-valent metal species is - conceptually different from heteroatom-based ligands - stabilized by π coordination to hydrocarbons. Potassium bis(anthracene)cobaltate 1 and -ferrate 2 can be viewed as synthetic precursors of quasi-"naked" anionic metal species; their aggregation is effectively impeded by (labile) coordination to the various π acceptors present in the hydrogenation reactions of unsaturated molecules (alkenes, arenes, carbonyl compounds). Kinetic studies, NMR spectroscopy, and poisoning studies of alkene hydrogenations support the formation of a homogeneous catalyst derived from 1 which is stabilized by the coordination of alkenes. This catalyst concept complements the use of complexes with heteroatom donor ligands for reductive processes. Especially high selectivities were observed in the hydrogenation of various alkenes, ketones, and imines with bis(anthracene) cobaltate(-I) [K(dme)2{Co(C14H10)2}] under mild conditions (1-5 mol% cat., 1-10 bar H2, 20-60°C). Mechanistic studies indicate the operation in alkene hydrogenations of a homogeneous catalyst formed by initial ligand exchange and stabilized by the coordination of π-acidic alkenes or arenes.
- Gaertner, Dominik,Welther, Alice,Rad, Babak Rezaei,Wolf, Robert,Von Wangelin, Axel Jacobi
-
supporting information
p. 3722 - 3726
(2014/04/17)
-
- 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)
-
- Intramolecular C(sp3)-N coupling by oxidation of benzylic C,N-dianions
-
What a couple! An intramolecular, C(sp3)-N coupling to afford azacycles is reported. This reaction proceeds through the oxidation of benzylic C,N-dianions with iodine and builds on an earlier discovery during the synthesis of the natural produc
- Jeffrey, Jenna L.,Bartlett, Emily S.,Sarpong, Richmond
-
supporting information
p. 2194 - 2197
(2013/03/28)
-
- 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)
-
- Rhenium-catalyzed insertion of terminal alkenes into a C(sp2)-H bond and successive transfer hydrogenation
-
Treatment of aromatic aldimines with terminal alkenes in the presence of a rhenium catalyst, [HRe(CO)4]n, gives 2-alkenylbenzylamines in good to excellent yields. This reaction proceeds via the insertion of the alkene into a C-H bond
- Kuninobu, Yoichiro,Nakahara, Takahiro,Yu, Peng,Takai, Kazuhiko
-
supporting information; experimental part
p. 348 - 351
(2011/02/17)
-
- Synthetic method for the preparation of 2-aminomethyl-1,3-diene derivatives through indium-mediated 1,3-butadien-2-ylation of imines
-
An efficient method for the preparation of a variety of 2-aminomethyl-1,3-dienes was developed through the reaction of imines with organoindium reagent generated in situ from indium and 1,3-dibromo-2-butyne. Three-component reactions of aldehydes, amines,
- Seomoon, Dong,Jaemyung A.,Lee, Phil Ho
-
supporting information; experimental part
p. 2401 - 2404
(2009/10/10)
-
- 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)
-
- Amine, Imine, and Aminocarbene Complexes of Platinum(II)
-
Solutions of the chloride-bridged binuclear platinum complexes (L=PMe2Ph or PBu3) readily react with the amines NH2Ph, 4-NO2C6H4NH2, 3-MeOC6H4NH2, NHPh2, or NH2Me to produce trans- in the presence or absence of phenylethyne.T
- Cross, Ronald J.,Davidson, Michael F.,Rocamora, Merce
-
p. 1147 - 1152
(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)
-