- Deoxygenative hydroboration of primary, secondary, and tertiary amides: Catalyst-free synthesis of various substituted amines
-
Transformation of relatively less reactive functional groups under catalyst-free conditions is an interesting aspect and requires a typical protocol. Herein, we report the synthesis of various primary, secondary, and tertiary amines through hydroboration of amides using pinacolborane under catalyst-free and solvent-free conditions. The deoxygenative hydroboration of primary and secondary amides proceeded with excellent conversions. The comparatively less reactive tertiary amides were also converted to the corresponding N,N-diamines in moderate yields under catalyst-free conditions, although alcohols were obtained as a minor product.
- Yi, Jaeeun,Kim, Hyun Tae,Jaladi, Ashok Kumar,An, Duk Keun
-
p. 129 - 132
(2021/11/17)
-
- Bicyclic (alkyl)(amino)carbene (BICAAC) as a metal-free catalyst for reduction of nitriles to amines
-
Bicyclic (alkyl)(amino)carbene (BICAAC) is introduced as a metal-free catalyst for the reduction of various nitriles to the corresponding amine hydrochloride salts in the presence of pinacolborane. Mechanistic investigations combining experiments and DFT calculations suggest a B-H addition to the carbene center, which acts as a carrier of the hydride source. This journal is
- Gautam, Nimisha,Logdi, Ratan,Mandal, Swadhin K.,Rajendran, N. M.,Sreejyothi, P.,Tiwari, Ashwani K.
-
supporting information
p. 3047 - 3050
(2022/03/14)
-
- Method for preparing amine compound by reducing amide compound
-
The invention relates to a method for preparing an amine compound by reducing an amide compound, which comprises the following steps: in a protective atmosphere, mixing the amide compound or cyclic amide, a zirconium metal catalyst and pinacol borane, carrying out amide reduction reaction at room temperature, and carrying out aftertreatment by using an ether solution of hydrogen chloride after 12-48 hours to obtain an amine hydrochloride compound. The method is simple to operate, low in cost, good in functional group tolerance and wide in substrate range.
- -
-
Paragraph 0226-0228
(2021/02/10)
-
- Reduction of Amides to Amines with Pinacolborane Catalyzed by Heterogeneous Lanthanum Catalyst La(CH2C6H4NMe2- o)3@SBA-15
-
Hydroboration of amides is a useful synthetic strategy to access the corresponding amines. In this contribution, it was found that the supported lanthanum benzyl material La(CH2C6H4NMe2-o)3@SBA-15 was highly active for the hydroboration of primary, secondary, and tertiary amides to amines with pinacolborane. These reactions selectively produced target amines and showed good tolerance for functional groups such as -NO2, -halogen, and -CN, as well as heteroatoms such as S and O. This reduction procedure exhibited the recyclable and reusable property of heterogeneous catalysts and was applicable to gram-scale synthesis. The reaction mechanisms were proposed based on some control experiments and the previous literature. This is the first example of hydroborative reduction of amides to amines mediated by heterogeneous catalysts.
- Guo, Chenjun,Zhang, Fangcao,Yu, Chong,Luo, Yunjie
-
p. 13122 - 13135
(2021/08/31)
-
- Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
-
A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
- Bera, Jitendra K.,Pandey, Pragati
-
supporting information
p. 9204 - 9207
(2021/09/20)
-
- Benzimidazole fragment containing Mn-complex catalyzed hydrosilylation of ketones and nitriles
-
The synthesis of a new bidentate (NN)–Mn(I) complex is reported and its catalytic activity towards the reduction of ketones and nitriles is studied. On comparing the reactivity of various other Mn(I) complexes supported by benzimidazole ligand, it was observed that the Mn(I) complexes bearing 6-methylpyridine and benzimidazole fragments exhibited the highest catalytic activity towards monohydrosilylation of ketones and dihydrosilylation of nitriles. Using this protocol, a wide range of ketones were selectively reduced to the corresponding silyl ethers. In case of unsaturated ketones, the chemoselective reduction of carbonyl group over olefinic bonds was observed. Additionally, selective dihydrosilylation of several nitriles were also achieved using this complex. Mechanistic investigations with radical scavengers suggested the involvement of radical species during the catalytic reaction. Stoichiometric reaction of the Mn(I) complex with phenylsilane revealed the formation of a new Mn(I) complex.
- Ganguli, Kasturi,Mandal, Adarsha,Sarkar, Bidisha,Kundu, Sabuj
-
-
- A State-of-the-Art Heterogeneous Catalyst for Efficient and General Nitrile Hydrogenation
-
Cobalt-doped hybrid materials consisting of metal oxides and carbon derived from chitin were prepared, characterized and tested for industrially relevant nitrile hydrogenations. The optimal catalyst supported onto MgO showed, after pyrolysis at 700 °C, magnesium oxide nanocubes decorated with carbon-enveloped Co nanoparticles. This special structure allows for the selective hydrogenation of diverse and demanding nitriles to the corresponding primary amines under mild conditions (e.g. 70 °C, 20 bar H2). The advantage of this novel catalytic material is showcased for industrially important substrates, including adipodinitrile, picolinonitrile, and fatty acid nitriles. Notably, the developed system outperformed all other tested commercial catalysts, for example, Raney Nickel and even noble-metal-based systems in these transformations.
- Formenti, Dario,Mocci, Rita,Atia, Hanan,Dastgir, Sarim,Anwar, Muhammad,Bachmann, Stephan,Scalone, Michelangelo,Junge, Kathrin,Beller, Matthias
-
supporting information
p. 15589 - 15595
(2020/10/02)
-
- Synthesis of Molybdenum Pincer Complexes and Their Application in the Catalytic Hydrogenation of Nitriles
-
A series of molybdenum(0), (I) and (II) complexes ligated by different PNP and NNN pincer ligands were synthesized and structurally characterized. Along with previously described Mo?PNP complexes Mo-1 and Mo-2, all prepared compounds were tested in the catalytic hydrogenation of aromatic nitriles to primary amines. Among the applied catalysts, Mo-1 is particularly well suited for the hydrogenation of electron-rich benzonitriles. Additionally, two aliphatic nitriles were transformed into the desired products in 80 and 86 percent, respectively. Moreover, catalytic intermediate Mo-1a was isolated and its role in the catalytic cycle was subsequently demonstrated.
- Leischner, Thomas,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
-
p. 4543 - 4549
(2020/07/13)
-
- Liquid-phase hydrogenation of nitriles to amines facilitated by a co(ii)/zn(0) pair: a ligand-free catalytic protocol
-
The given report introduces a simple and user-friendly in situ method for the production of catalytically active cobalt particles. The approach circumvents the use of air-and moisture-sensitive reductants as well as the application of anhydrous Co-precursor salts. Accordingly, the described catalytic system is readily assembled under open-flask conditions by simply combining the components in the reaction vessel. Therefore, the arduous charging procedure of the reaction autoclave in a glovebox under an inert gas atmosphere is no longer necessary. In fact, the catalytically active material is obtained upon treatment of readily available Co(OAc)2·4 H2O with benign commercial Zn powder. The catalytic performance of the resultant material was tested in the heterogeneous hydrogenation of nitriles to the corresponding primary amines. Both activity and selectivity of the cobalt catalyst are significantly enhanced if a triflate-based Lewis acid and ammonia is added to the reaction mixture.
- Timelthaler, Daniel,Topf, Christoph
-
p. 11604 - 11611
(2019/10/02)
-
- Rapid Continuous Ruthenium-Catalysed Transfer Hydrogenation of Aromatic Nitriles to Primary Amines
-
A continuous flow method for the selective reduction of aromatic nitriles to the corresponding amine is reported. The method is based on a ruthenium-catalysed transfer-hydrogenation process, requires no additives, and uses isopropanol as both solvent and reducing agent. The process utilizes 1 mol% of the commercially available [Ru(p -cymene)Cl 2 ] 2, with a residence time of ca. 9 min, and a throughput of 50 mmol/h. The method was successfully applied to a range of aromatic nitriles providing the corresponding primary amines in good yields.
- Labes, Ricardo,González-Calderón, Davir,Battilocchio, Claudio,Mateos, Carlos,Cumming, Graham R.,De Frutos, Oscar,Rincón, Juan A.,Ley, Steven V.
-
supporting information
p. 2855 - 2858
(2017/10/06)
-
- Boron-Catalyzed Silylative Reduction of Nitriles in Accessing Primary Amines and Imines
-
Silylative reduction of nitriles was studied under transition metal-free conditions by using B(C6F5)3 as a catalyst with hydrosilanes as a reductant. Alkyl and (hetero)aryl nitriles were efficiently converted to primary amines or imines under mild conditions. The choice of silanes was found to determine the selectivity: while a full reduction of nitriles was highly facile, the use of sterically bulky silanes allowed for the partial reduction leading to N-silylimines.
- Gandhamsetty, Narasimhulu,Jeong, Jinseong,Park, Juhyeon,Park, Sehoon,Chang, Sukbok
-
p. 7281 - 7287
(2015/07/28)
-
- 1,2,3-Trimethoxypropane, a glycerol-based solvent with low toxicity: New utilization for the reduction of nitrile, nitro, ester, and acid functional groups with TMDS and a metal catalyst
-
1,2,3-Trimethoxypropane (1,2,3-TMP) was prepared from glycerol in one step in good yield and selectivity by phase transfer catalysis. According to OECD guidelines, a toxicity study was realized for this compound. It revealed that 1,2,3-TMP has a low acute toxicity, no skin sensitization, no mutagenicity and no ecotoxicity in an aquatic environment. This compound was also used as a solvent for the reduction of organic functions using either aluminium hydride or 1,1,3,3-tetramethyldisiloxane (TMDS) as a benign hydride source. In particular, a new process for the reduction of nitriles to amines in 2-MeTHF and in 1,2,3-TMP was developed, using TMDS in combination with copper triflate (Cu(OTf)2).
- Sutter, Marc,Pehlivan, Leyla,Lafon, Romain,Dayoub, Wissam,Raoul, Yann,Metay, Estelle,Lemaire, Marc
-
supporting information
p. 3020 - 3026
(2013/11/06)
-
- Synthesis of azide-armed α-1-C-alkyl-imino-d-xylitol derivatives as key building blocks for the preparation of iminosugar click conjugates
-
Azide-armed α-1-C-alkyl-imino-d-xylitol derivatives have been efficiently prepared by way of olefin cross-metathesis in eight to nine steps and in an overall yield of 19% to 26% from 2,3,4-tri-O-benzyl-d-xylopyranose. Optimization of cleavage conditions of N-NAP-protected tertiary amines using DDQ in CH2Cl2-H2O (18:1) is also reported. The iminosugars synthesized will be used as key building blocks in the synthesis of multivalent iminosugars of biological interest by way of Cu(I)-catalyzed azide-alkyne cycloaddition reaction.
- Decroocq, Camille,Laparra, Laura Mamani,Rodriguez-Lucena, David,Compain, Philippe
-
experimental part
p. 559 - 574
(2012/06/01)
-
- Novel scaffolds for beta-helix mimicry
-
Functionalized pyridazine derivatives having a low molecular weight and pharmaceutical compositions thereof are useful as alpha-helix mimetics and for treating conditions and/or disorders mediated by alpha-helix-binding receptors and proteins.
- -
-
Page/Page column 31
(2008/06/13)
-
- Anthranilic acid derivatives as inhibitors of the cGMP-phosphodiesterase
-
Compounds of formula (I) STR1where R 1 is hydrogen; R 2 is nitro, cyano or halo(lower)alkyl; R 3 is phenyl substituted with one or more substituents selected from halogen, cyano and lower alkoxy; A is a lower alkylene group; R 4 is a group CR 6 R 7 R 8 wherein R 6 and R 7 form, together with the carbon atom to which they are attached a cycloalkyl group optionally substituted with hydroxy, lower alkoxy or a lower alkanoylamino; and R 8 is hydrogen; its prodrug and a salt thereof.
- -
-
-