- Trimethyl Borate-Catalyzed, Solvent-Free Reductive Amination
-
Solvent-free reductive amination of aldehydes and ketones with aliphatic and aromatic amines in high-to-excellent yields has been achieved with sub-stoichiometric trimethyl borate as promoter and ammonia borane as reductant.
- Ramachandran, P. Veeraraghavan,Choudhary, Shivani,Singh, Aman
-
p. 4274 - 4280
(2021/03/09)
-
- Discovery of tert-amine-based RORγt agonists
-
The nuclear receptor retinoic acid receptor-related orphan receptor gamma-t (RORγt) is a transcription factor regulating Th17 cell differentiation and proliferation from naive CD4+ T cells. Since Th17 cells have demonstrated the antitumor efficacy by eliciting remarkable activation of CD8+ T cells, RORγt agonists could be applied as potential small molecule therapeutics for cancer immunotherapy. Based on the previously reported RORγt agonist 1 and its resolved co-crystal structure, a series of new tertiary amines were designed, synthesized and biologically evaluated, yielding optimal moieties with improved chemical properties and biological responses. The combination of these optimal moieties resulted in identification of novel RORγt agonists such as 8b with further elevated RORγt agonism responses at a target-based level as well as in cell-based assays, which provided some structural knowledge for further optimization of RORγt agonists as small molecule therapeutics for cancer immunotherapy.
- Qiu, Ruomeng,Yu, Mingcheng,Gong, Juwen,Tian, Jinlong,Huang, Yafei,Wang, Yonghui,Xie, Qiong
-
-
- Highly economical and direct amination of sp3carbon using low-cost nickel pincer catalyst
-
Developing more efficient routes to achieve C-N bond coupling is of great importance to industries ranging from products in pharmaceuticals and fertilizers to biomedical technologies and next-generation electroactive materials. Over the past decade, improvements in catalyst design have moved synthesis away from expensive metals to newer inexpensive C-N cross-coupling approaches via direct amine alkylation. For the first time, we report the use of an amide-based nickel pincer catalyst (1) for direct alkylation of amines via activation of sp3 C-H bonds. The reaction was accomplished using a 0.2 mol% catalyst and no additional activating agents other than the base. Upon optimization, it was determined that the ideal reaction conditions involved solvent dimethyl sulfoxide at 110 °C for 3 h. The catalyst demonstrated excellent reactivity in the formation of various imines, intramolecularly cyclized amines, and substituted amines with a turnover number (TON) as high as 183. Depending on the base used for the reaction and the starting amines, the catalyst demonstrated high selectivity towards the product formation. The exploration into the mechanism and kinetics of the reaction pathway suggested the C-H activation as the rate-limiting step, with the reaction second-order overall, holding first-order behavior towards the catalyst and toluene substrate.
- Brandt, Andrew,Rangumagar, Ambar B.,Szwedo, Peter,Wayland, Hunter A.,Parnell, Charlette M.,Munshi, Pradip,Ghosh, Anindya
-
p. 1862 - 1874
(2021/01/20)
-
- Cobalt encapsulated in N?doped graphene sheet for one-pot reductive amination to synthesize secondary amines
-
To develop an efficient base-metal reductive amination catalyst for synthesis of secondary amines is still a major challenge. In this study, an efficient N-doped graphene sheet-coated cobalt catalyst (Co@CN-800) was developed through a simple pyrolysis process, which could gave 99.5 % yield of N-benzylaniline by one-pot reductive amination of nitrobenzene with benzaldehyde during at least 5 cycles. Catalyst characterization and control experiments confirmed that the robust catalytic performance of the catalyst is probably due to the synergy effect of in situ generated Co-Nx encapsulated in N?doped graphene layer and appropriate meso-pore structure. Additionally, The substrate adaptability of the catalyst was proved since a variety of corresponding secondary amines were smoothly obtained under relatively mild conditions, which makes the secondary amine synthesis strategy based on Co@CN-800 shows excellent application prospect.
- Liu, Lin,Li, Wenxiu,Qi, Ran,Zhu, Qingqing,Li, Jing,Fang, Yuzhen,Kong, Xiangjin
-
-
- One-pot, chemoselective synthesis of secondary amines from aryl nitriles using a PdPt-Fe3O4nanoparticle catalyst
-
We have developed a new catalytic method for the one-pot, cascade synthesis of unsymmetrical secondary amines via the reductive amination of aryl nitriles with nitroalkanes using a PdPt-Fe3O4 nanoparticle (NP) catalyst. The use of a bimetallic catalyst resulted in enhanced reactivity and selectivity compared to that of either monometallic Pd-Fe3O4 or the Pt-Fe3O4 NP catalyst. Using this bimetallic catalytic system, we were successful in the synthesis of various unsymmetrical secondary amines under mild conditions. However, aryl nitriles containing an electron-donating substituent were rather resistant to the reductive amination, and when hexafluoroisopropanol (HFIP) was used as a co-solvent, the reaction selectivity and yield for unsymmetrical secondary amines increased dramatically. Using the catalyst system, one-pot, gram-scale synthesis of indole was possible from 2-nitrophenylacetonitrile. Due to the magnetic property of the Fe3O4 support, the bimetallic catalyst could easily be recycled using an external magnet at least four times.
- Byun, Sangmoon,Cho, Ahra,Cho, Jin Hee,Kim, B. Moon
-
p. 4201 - 4209
(2020/09/23)
-
- Tertiary amine derivative or salt thereof, preparation method and application thereof
-
Belonging to the technical field of chemical medicine, the invention relates to a tertiary amine RORgamma t regulator, in particular to a new tertiary amine compound or salt thereof with RORgamma t inhibition or agonist activity shown as general formula I, a preparation method and a pharmaceutical composition thereof. The tertiary amine compound or a salt thereof provided by the invention can be used for preparation of drugs treating or preventing RORgamma t receptor related diseases.
- -
-
Paragraph 0320; 0323; 324; 0325
(2019/01/24)
-
- Methyl-triflate-mediated dearylmethylation of: N -(arylmethyl)carboxamides via the retro-Mannich reaction induced by electrophilic dearomatization/rearomatization in an aqueous medium at room temperature
-
We have developed a protocol for the dearylmethylation of N-(arylmethyl)carboxamides under metal-free conditions in an aqueous medium at room temperature. This protocol involves methyl triflate-mediated successive C-C and C-N bond cleavages (retro-Mannich reaction) induced by electrophilic dearomatization/rearomatization. The dearomatization/rearomatization strategy can be expected to inspire the development of novel transformations based on the C-C bond cleavage in an environmentally benign manner.
- Peng, Hui,Ma, Jinhui,Luo, Wenkun,Zhang, Guangwen,Yin, Biaolin
-
supporting information
p. 2252 - 2256
(2019/05/17)
-
- Biocatalytic N-Alkylation of Amines Using Either Primary Alcohols or Carboxylic Acids via Reductive Aminase Cascades
-
The alkylation of amines with either alcohols or carboxylic acids represents a mild and safe alternative to the use of genotoxic alkyl halides and sulfonate esters. Here we report two complementary one-pot systems in which the reductive aminase (RedAm) from Aspergillus oryzae is combined with either (i) a 1° alcohol/alcohol oxidase (AO) or (ii) carboxylic acid/carboxylic acid reductase (CAR) to affect N-alkylation reactions. The application of both approaches has been exemplified with respect to substrate scope and also preparative scale synthesis. These new biocatalytic methods address issues facing alternative traditional synthetic protocols such as harsh conditions, overalkylation and complicated workup procedures.
- Ramsden, Jeremy I.,Heath, Rachel S.,Derrington, Sasha R.,Montgomery, Sarah L.,Mangas-Sanchez, Juan,Mulholland, Keith R.,Turner, Nicholas J.
-
p. 1201 - 1206
(2019/01/21)
-
- Direct Reductive Amination of Carbonyl Compounds with H2 Using Heterogeneous Catalysts in Continuous Flow as an Alternative to N-Alkylation with Alkyl Halides
-
A general continuous-flow procedure for direct reductive amination of secondary and primary amines with aromatic and aliphatic aldehydes as well as ketones is reported. The use of hydrogen gas and commercially available Pt/C as a heterogeneous catalyst is a key. In addition to exhibiting an excellent functional group tolerance, this method allows the fast formation of C?N bonds without production of any hazardous chemical waste. Applications to the synthesis of key intermediates toward active pharmaceutical ingredients (Donepezil and Arformoterol/Tamsulosin) are also described. (Figure presented.).
- Laroche, Benjamin,Ishitani, Haruro,Kobayashi, Shū
-
supporting information
p. 4699 - 4704
(2018/12/04)
-
- Direct Reductive N-Functionalization of Aliphatic Nitro Compounds
-
The first general protocol for the direct reductive N-functionalization of aliphatic nitro compounds is presented. The nitro group is partially reduced to a nitrenoid, with a mild and readily available combination of B2pin2 and zinc organyls. Thereby, the formation of an unstable nitroso intermediate is avoided, which has so far severely limited reductive transformations of aliphatic nitro compounds. The reaction is concluded by an electrophilic amination of zinc organyls.
- Rauser, Marian,Ascheberg, Christoph,Niggemann, Meike
-
p. 3970 - 3974
(2018/02/26)
-
- Inexpensive and rapid hydrogenation catalyst from CuSO4/CoCl2 — Chemoselective reduction of alkenes and alkynes in the presence of benzyl protecting groups
-
The simple reduction of a number of alkenes and alkynes was performed with a typical reaction time of 20 min using a copper-cobalt catalytic system. The reduction did not cleave benzyl protecting groups which are usually vulnerable to catalytic hydrogenation reactions. The catalyst can be prepared in situ by reduction of the inexpensive precursor salts CuSO4 and CoCl2 with NaBH4. Sodium borohydride was also used as an easily handled hydrogen source for the catalytic reductions. No pressure, heating or inert atmosphere is required and purification/catalyst removal is achieved using extraction procedures, making this approach simple and efficient.
- Ficker, Mario,Svenningsen, S?ren W.,Larribeau, Thomas,Christensen, J?rn B.
-
supporting information
p. 1125 - 1129
(2018/02/21)
-
- One-pot Reductive Amination of carbonyl Compounds with Nitro Compounds by Transfer Hydrogenation over Co–Nx as catalyst
-
A new method was developed for the synthesis of secondary amines through the one-pot reductive amination of carbonyl compounds with nitro compounds using formic acid as the hydrogen donor over a heterogeneous non-noble-metal catalyst (Co-Nx/C-800-AT, generated by the pyrolysis of the cobalt phthalocyanine/silica composite at 800°C under a N2 atmosphere and subsequent etching by HF). Both nitrogen and cobalt were of considerable importance in the transfer hydrogenation reactions with formic acid.
- Zhou, Peng,Zhang, Zehui
-
p. 1892 - 1897
(2017/05/16)
-
- One-pot reductive amination of carbonyl compounds with nitro compounds with CO/H2O as the hydrogen donor over non-noble cobalt catalyst
-
The one-pot reductive amination of carbonyl compounds with nitro compounds over heterogeneous non-noble metal catalysts was developed for the first time by transfer hydrogenation with CO/H2O as the hydrogen donor. Nitrogen-doped carbon supported cobalt nanoparticles were observed to be active toward this reaction, affording structurally-diverse secondary amines with high yields. Kinetic studies revealed that the transfer hydrogenation of imines (C[dbnd]N bonds) was the rate-determining step. Reaction mechanism studies indicated that both nitrogen and cobalt nanoparticles were important for the transfer hydrogenation with CO/H2O to generate the proton (N[sbnd]H+) and hydride (Co[sbnd]H?) as the active species. Furthermore, the heterogeneous cobalt catalyst was highly stable without the loss of its catalytic activity during the recycling experiments.
- Zhou, Peng,Yu, Changlin,Jiang, Liang,Lv, Kangle,Zhang, Zehui
-
p. 264 - 273
(2017/06/23)
-
- Unsupported Nanoporous Gold Catalyst for Chemoselective Hydrogenation Reactions under Low Pressure: Effect of Residual Silver on the Reaction
-
For the first time, H-H dissociation on an unsupported nanoporous gold (AuNPore) surface is reported for chemoselective hydrogenation of C=C, C=C, C=N, and C=O bonds under mild conditions (8 atm H2 pressure, 90 °C). Silver doping in AuNPore, which was inevitable for its preparation through a process of dealloying of Au-Ag alloy, exhibited a remarkable difference in catalytic activity between two catalysts, Au>99Ag1NPore and Au90Ag10NPore.The former was more active and the latter less active in H2 hydrogenation, while the reverse tendency was observed for O2 oxidation. This marked contrast between H2 reduction and O2 oxidation is discussed. Further, Au>99Ag1NPore showed a high chemoselectivity toward reduction of terminal alkynes in the presence of internal alkynes which was not achieved using supported gold nanoparticle catalysts and other previously known methods. Reductive amination, which has great significance in synthesis of amines due to its atom-economical nature, was also realized using Au>99Ag1NPore, and the Au>99Ag1NPore/H2 system showed a preference for the reduction of aldehydes in the presence of imines. In addition to this high chemoselectivity, easy recovery and high reusability of AuNPore make it a promising heterogeneous catalyst for hydrogenation reactions.
- Takale, Balaram S.,Feng, Xiujuan,Lu, Ye,Bao, Ming,Jin, Tienan,Minato, Taketoshi,Yamamoto, Yoshinori
-
supporting information
p. 10356 - 10364
(2016/08/31)
-
- Mild Metal-Free Hydrosilylation of Secondary Amides to Amines
-
The combination of amide activation by Tf2O with B(C6F5)3-catalyzed hydrosilylation with TMDS constitutes a method for the one-pot reduction of secondary amides to amines under mild conditions. The method displays a broad applicability for the reduction of many types of substrates, and shows good compatibility and excellent chemoselectivity for many sensitive functional groups. Reductions of a multifunctionalized α,β-unsaturated amide obtained from another synthetic methodology, and a C-H functionalization product produced the corresponding amines in good to excellent yield. Chemoselective reduction of enantiomeric pure (ee >99%) tetrahydro-5-oxo-2-furaneamides yielded 5-(aminomethyl)dihydrofuran-2(3H)-ones in a racemization-free manner. The latter were converted in one pot to N-protected 5-hydroxypiperidin-2-ones, which are building blocks for the synthesis of many natural products. Further elaboration of an intermediate led to a concise four-step synthesis of -epi-pseudoconhydrine.
- Huang, Pei-Qiang,Lang, Qi-Wei,Wang, Yan-Rong
-
p. 4235 - 4243
(2016/06/09)
-
- One-pot synthesis of organic disulfides (disulfanes) from alkyl halides using sodium sulfide trihydrate and hexachloroethane or carbon tetrachloride in the poly(ethylene glycol) (PEG-200)
-
Abstract Symmetric disulfides are produced by treating their corresponding organic halides including benzylic, allylic, primary and secondary halides with Na2S·3H2O and C2Cl6 or CCl4 in PEG-200 at room temperature in high yields.
- Abbasi, Mohammad,Mohammadizadeh, Mohammad Reza,Moosavi, Hekmat,Saeedi, Narges
-
p. 1185 - 1190
(2015/03/31)
-
- Electrochemical deoxygenation of aromatic amides and sulfoxides
-
The electrochemical deoxygenation of a broad range of aromatic amides was achieved under mild conditions on lead cathodes. Under the optimized reaction conditions, acetal, thienyl, and ether moieties are tolerated. Furthermore, the reduction protocol can be applied to aromatic and aliphatic sulfoxides to obtain the corresponding sulfides. For both aromatic amides and sulfoxides, the deoxygenation reaction ensues without the use of expensive catalysts or hazardous reducing agents. Owing to the high selectivity of the process, simple extraction is sufficient to isolate the product from the substrate. The straightforward purification protocol, the coformation of water, and the use of electric current instead of reducing agents render our method environmentally friendly and economically beneficial. Copyright
- Edinger, Carolin,Waldvogel, Siegfried R.
-
supporting information
p. 5144 - 5148
(2014/10/15)
-
- Palladium on activated carbon catalyzed reductive amination of aldehydes and ketones by triethylsilane
-
Various aldehydes and ketones were efficiently transformed into the corresponding amines using amine derivatives in the presence of triethylsilane and a catalytic amount of palladium on activated carbon in ethanol. The proposed method provides a one-pot synthesis of various amines in excellent yields after short reaction times.
- Mirza-Aghayan, Maryam,Tavana, Mahdieh Molaee,Rahimifard, Mahshid,Boukherroub, Rabah
-
p. 113 - 115
(2014/02/14)
-
- Continuous reductions and reductive aminations using solid NaBH4
-
Most successful reactions carried out under continuous flow conditions mix homogeneous solutions yielding homogeneous products. Using solids is avoided to prevent pump and reactor clogging; even though solid reagents may often be the best choice for a given transformation. Here we demonstrate that by pumping aldehydes, ketones, or in situ formed imines through a specially formulated NaBH4 column results in efficient reductions. The column design and performance characteristics, along with substrate scope, are discussed.
- Gilmore, Kerry,Vukeli, Stella,McQuade, D. Tyler,Koksch, Beate,Seeberger, Peter H.
-
p. 1771 - 1776
(2015/02/02)
-
- Synthesis and biological activity of some novel substituted quinazoline derivatives
-
A new series of 4-N-(substituted benzyl)-2-phenyl-N-propylquinazolines were synthesized. The structures of the synthesized compounds were confirmed by IR, 1H NMR, 13C NMR and mass spectral analysis. All the synthesized compounds were screened for their analgesic and anti-inflammatory activity. Among the synthesized compounds 5c, 5h and 5o exhibited significant analgesic activity at 60 and 90 minutes reading, while compounds 5g, 5k and 5l exhibited significant anti-inflammatory activity at 3rd and 4th hr reading.
- Srivastav, Maneesh Kumar,Rajeeva,Salahuddin, Md.,Srinivasulu,Shanta Kumar
-
p. 115 - 118
(2019/01/21)
-
- Discovery of tertiary amine and indole derivatives as potent RORγt inverse agonists
-
A novel series of tertiary amines as retinoid-related orphan receptor gamma-t (RORγt) inverse agonists was discovered through agonist/inverse agonist conversion. The level of RORγt inhibition can be enhanced by modulating the conformational disruption of H12 in RORγt LBD. Linker exploration and rational design led to the discovery of more potent indole-based RORγt inverse agonists.
- Yang, Ting,Liu, Qian,Cheng, Yaobang,Cai, Wei,Ma, Yingli,Yang, Liuqing,Wu, Qianqian,Orband-Miller, Lisa A.,Zhou, Ling,Xiang, Zhijun,Huxdorf, Melanie,Zhang, Wei,Zhang, Jing,Xiang, Jia-Ning,Leung, Stewart,Qiu, Yang,Zhong, Zhong,Elliott, John D.,Lin, Xichen,Wang, Yonghui
-
supporting information
p. 65 - 68
(2014/02/14)
-
- Palladium(II) acetate-catalyzed reduction of imines to the corresponding amines by triethylsilane
-
Reduction of a variety of imine compounds with triethylsilane in the presence of catalytic amounts of palladium(II) acetate in ethanol resulted in the formation of the corresponding amines in excellent yields after short reaction times. Copyright
- Mirza-Aghayan, Maryam,Boukherroub, Rabah,Rahimifard, Mahshid
-
p. 174 - 176
(2013/05/09)
-
- Cooperative catalysis with aldehydes and copper: Development and application in aerobic oxidative C-H amination at room temperature
-
A conceptually new cooperative catalytic system via a synergistic combination of aldehyde and copper catalysis has been established based on systemic mechanistic studies. This new cooperative catalysis has been successfully applied in the direct aerobic oxidative C-H amination of azoles at room temperature, which was previously realized under harsh conditions. Mechanistic studies including isotopic labeling experiments and kinetic isotope effect (KIE) experiments support a reaction pathway that involves formation of an aminal, hydrolysis of the aminal to generate the copper-amide species, subsequent C-H amination and re-oxidation of copper(I) to copper(II) by oxygen. It not only provides an efficient method to realize the oxidative C-H amination of benzoxazoles with free amines at room temperature, but also paves the way for establishing new C-N bond formation reactions by using this efficient cooperative catalysis. Copyright
- Xie, Yinjun,Qian, Bo,Xie, Pan,Huang, Hanmin
-
supporting information
p. 1315 - 1322
(2013/06/27)
-
- Replacing phosphorus with sulfur for the efficient hydrogenation of esters
-
Catalyst tune-up: A readily available, air-stable amino-sulfide catalyst, [RuCl2(PPh3){HN(C2H4SEt) 2}], has been developed. This complex displays outstanding efficiency for the hydrogenation of a broad range of substrates with C-X bonds (esters, ketones, imines), as well as for the acceptorless dehydrogenative coupling of ethanol to ethyl acetate (see scheme). Copyright
- Spasyuk, Denis,Smith, Samantha,Gusev, Dmitry G.
-
supporting information
p. 2538 - 2542
(2013/04/10)
-
- Reductive amination of aldehydes and ketones with primary amines by using lithium amidoborane as reducing reagent
-
A variety of secondary amines were obtained in high isolated yields in the reductive amination of aldehydes and ketones by using lithium amidoborane as reducing agent. Compared to ammonia borane, lithium amidoborane has higher reducibility, and thus, exhibits faster reaction rate.
- Xu, Weiliang,Zheng, Xueli,Wu, Guotao,Chen, Ping
-
p. 1775 - 1780
(2012/10/29)
-
- Acceptorless dehydrogenative coupling of ethanol and hydrogenation of esters and imines
-
This paper presents an outstanding air-stable ruthenium catalyst that has unprecedented efficiency (TON up to 17-000) for acceptorless dehydrogenative coupling of ethanol, yielding ethyl acetate and hydrogen gas, and for hydrogenation of esters and imines at 40 °C while using as low as 50 ppm [Ru].
- Spasyuk, Denis,Gusev, Dmitry G.
-
p. 5239 - 5242,4
(2020/08/31)
-
- Novel caffeic acid amide antioxidants: Synthesis, radical scavenging activity and performance under storage and frying conditions
-
Twelve novel dihydro-caffeic acid amides were synthesised in good yields and fully characterised by 1H NMR, 13C NMR, and MS. Their radical scavenging activities were assessed by DPPH assay. Additionally, their abilities to protect polyunsaturated oils under accelerated storage and frying conditions were evaluated. All the new compounds possessed significantly higher radical scavenging activities than α-tocopherol and butylated hydroxytoluene (BHT). The radical scavenging activity of N-decyl-N-(3,5- dimethoxy-4-hydroxybenzyl)-3-(3,4-dihydroxyphenyl) propanamide was 1.7 and 4 times higher than α-tocopherol and BHT, respectively. At the end of the storage period, the respective amounts of hydroperoxides in canola oil triacylglycerols (CTAG) fortified with α-tocopherol and BHT was 6.1 and 1.4 times higher, respectively, than CTAG containing the amide. The frying test showed that CTAG containing N-decyl-N-benzyl-3-(3,4-dihydroxybenzyl) propanamide was 1.3, 1.4, and 1.6 times more stable compared to oil fortified with dihydro-caffeic acid, α-tocopherol and BHT, respectively, as assessed by the amounts of the total polar compounds. Moreover, these compounds were remarkably thermally stable, making them suitable for frying applications.
- Aladedunye, Felix,Catel, Yohann,Przybylski, Roman
-
experimental part
p. 945 - 952
(2012/05/05)
-
- Electrochemical cleavage of sulfonamides: An efficient and tunable strategy to prevent β-fragmentation and epimerization
-
The electrochemical reduction of sensitive sulfonamides is described. The addition of a benzoyl group on the nitrogen atom facilitates the reductive cleavage of sulfonamides preventing β-fragmentation and epimerization. This strategy was successfully applied to the cyclopropylamine and to α-amino stannanes.
- Viaud, Pierre,Coeffard, Vincent,Thobie-Gautier, Christine,Beaudet, Isabelle,Galland, Nicolas,Quintard, Jean-Paul,Le Grognec, Erwan
-
scheme or table
p. 942 - 945
(2012/03/26)
-
- Iridium-catalysed amine alkylation with alcohols in water
-
Amines have been directly alkylated with alcohols using 1 mol% [Cp*IrI2]2 catalyst in water in the absence of base or other additives. The Royal Society of Chemistry 2010.
- Saidi, Ourida,Blacker, A. John,Farah, Mohamed M.,Marsden, Stephen P.,Williams, Jonathan M. J.
-
supporting information; experimental part
p. 1541 - 1543
(2010/06/12)
-
- Direct reductive amination of aldehydes and ketones with 2,4-ionene-based borohydride exchange resin as a novel polymer-supported reducing agent
-
Direct reductive amination of aldehydes and ketones were accomplished efficiently using high-capacity, ionene-based, polymer-supported borohydride reagent in isopropyl alcohol at reflux under neutral conditions. The reagent is easily prepared by mixing aqueous solution of 2,4-ionene bromide with an alkaline solution of sodium borohydride at room temperature. The generality of reaction was established using both aliphatic and aromatic aldehydes, ketones, and amines. Copyright Taylor & Francis Group, LLC.
- Tajbakhsh, Mahmood,Lakouraj, Moslem Mansour,Mahalli, Majid Shabani
-
p. 1976 - 1983
(2008/09/21)
-
- Ionene-bound borohydrides: Efficient, selective, and versatile polymer-supported reducing agents
-
Reduction of structurally different carbonyl compounds, such as aldehydes, ketones, α,β-unsaturated enals and enones, acid chlorides, and imines was accomplished efficiently using high capacity ionene based borohydride reagents. Aldehydes and imines were reduced to the corresponding alcohols and amines in excellent yields in methanol at ambient temperature while ketones and acid chlorides were reduced in iso-propanol and THF-MeOH at reflux. Chemoselective reduction of aldehydes over ketones was achieved successfully with these reagents. Complete regioselectivity was also observed in the reduction of α,β-unsaturated aldehydes and ketones.
- Lakouraj, Moslem M.,Tajbakhsh, Mahmood,Mahalli, Majid S.
-
p. 117 - 123
(2008/09/21)
-
- Mild electrochemical deprotection of N-phenylsulfonyl N-substituted amines derived from (R)-phenylglycinol
-
The electrochemical reduction of N-phenylsulfonyl N-substituted amines in a protic medium under constant cathodic potential was found to be a mild desulfonylation method, which is able to challenge the chemical ones. The influence of the nature of the N-substituents was considered in order to clarify the mechanistic aspects and to evaluate the scope of the method. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Coeffard, Vincent,Thobie-Gautier, Christine,Beaudet, Isabelle,Le Grognec, Erwan,Quintard, Jean-Paul
-
p. 383 - 391
(2008/09/18)
-
- One-pot reductive amination of aldehydes and ketones using N-methyl-piperidine zinc borohydride (ZBNMPP) as a new reducing agent
-
A one-pot reductive amination of aldehydes and ketones using N-methyl piperidine zinc borohydride as a new and stable reducing agent is described. The reaction has been carried out in methanol at room temperature under neutral conditions. Georg Thieme Verlag Stuttgart.
- Alinezhad, Heshmatollah,Tajbakhsh, Mahmoud,Zamani, Reza
-
p. 431 - 434
(2007/10/03)
-
- Reductive amination of aldehydes and ketones with sodium borohydride supported onto HZSM-5 zeolite under microwave irradiation in a solvent free system
-
Sodium borohydride supported onto a HZSM-5 zeolite is presented as a general reducing agent for the reductive amination of aldehydes and ketones under microwave irradiation in solventless system. Copyright Taylor & Francis Inc.
- Oskooie, Hossein A.,Amiri, Somaih Solemani,Heravi, Majid M.,Ghassemzadeh, Mitra
-
p. 2047 - 2050
(2007/10/03)
-
- Effective reductive amination of carbonyl compounds with hydrogen catalyzed by iridium complex in organic solvent and in ionic liquid
-
The direct reductive amination (DRA) of carbonyl compounds with amines has been achieved using homogenous iridium catalyst and gaseous hydrogen. It appeared that the cationic iridium catalyst, [Ir(cod)2]BF 4, without any other ligands was sufficient for the reaction. For the DRA of the ketone substrates, an ionic liquid, [Bmim]BF4, was found to be superior to the other organic solvent used. Especially, the counter anion of the ionic liquid has a significant influence on the selectivity, and at the same time, a high reaction temperature was found to be crucial for the excellent selectivity.
- Imao, Daisuke,Fujihara, Shoichiro,Yamamoto, Takeshi,Ohta, Tetsuo,Ito, Yoshihiko
-
p. 6988 - 6992
(2007/10/03)
-
- TACHYKININ RECEPTOR ANTAGONISTS
-
The present invention relates to selective NK-1 receptor antagonists of Formula (I) or a pharmaceutically acceptable salt thereof, for the treatment of disorders associated with an excess of tachykinins.
- -
-
-
- Use of CaH2 as a reductive hydride source: Reduction of ketones and imines with CaH2/ZnX2 in the presence of a Lewis acid
-
A new combination reagent of CaH2/ZnX2 effectively reduced a variety of ketones and imines to the corresponding alcohols and amines, respectively, in the presence of a catalytic amount of a Lewis acid such as Ti(O-i-Pr)4, Al(O-i-Pr)3, B(O-i-Pr)3 and ZnF2. Published by Elsevier Ltd.
- Aida, Toshio,Kuboki, Norikatsu,Kato, Kenji,Uchikawa, Wataru,Matsuno, Chikashi,Okamoto, Sentaro
-
p. 1667 - 1669
(2007/10/03)
-
- One-pot reductive amination of aldehydes and ketones with α-picoline-borane in methanol, in water, and in neat conditions
-
A one-pot reductive amination of aldehydes and ketones with amines using α-picoline-borane as a reducing agent is described. The reaction has been carried out in MeOH, in H2O, and in neat conditions in the presence of small amounts of AcOH. This is a highly efficient and mild procedure that is applicable for a wide variety of substrates. In particular, this is the first successful demonstration that this type of reaction can be carried out in water and in neat conditions.
- Sato, Shinya,Sakamoto, Takeshi,Miyazawa, Etsuko,Kikugawa, Yasuo
-
p. 7899 - 7906
(2007/10/03)
-
- Preparation of benzolactams by Pd(OAC)2-catalyzed direct aromatic carbonylation
-
We developed a new method for Pd(II)-catalyzed direct aromatic carbonylation in a phosphine-free catalytic system using Pd(OAc)2 and Cu(OAc)2 in an atmosphere of CO gas containing air. The carbonylation proceeded with ortho-palladation, inducing a remarkable site selectivity to afford a variety of five- or six-membered benzolactams from secondary ω-arylalkylamines, such as N-alkylbenzylamines or N-alkylphenethylamines. Copyright
- Orito, Kazuhiko,Horibata, Akiyoshi,Nakamura, Takatoshi,Ushito, Harumi,Nagasaki, Hideo,Yuguchi, Motoki,Yamashita, Satoshi,Tokuda, Masao
-
p. 14342 - 14343
(2007/10/03)
-
- Hydroamination of carbonyl compounds with oximes
-
N-alkyl(cycloalkyl)benzylamines, p-fluorobenzylamines, (1-phenylethyl) amines, [1-(p-fluorophenyl)ethyl]amines were synthesized by hydroamination of aldehydes and ketones with oximes.
- Tarasevich,Kozlov
-
p. 379 - 383
(2007/10/03)
-
- Dichlorobis(1,4-diazabicyclo[2.2.2]octane)(tetrahydroborato)zirco- nium(IV), [Zr(BH4)2Cl2(dabco)2](ZrBDC), as a new, stable, and versatile bench top reducing agent: Reduction of imines and enamines, reductive amination of aldehydes and ketones and reductive methylation of amines
-
The reducing agent is easily prepared in an almost quantitative yield from commercially available starting materials. This compound is stable under mild aqueous acidic conditions (pH 4-6) and survives in H2O for several days without losing its reducing abilities. ZrBDC has been successfully used for the reduction of imines and enamines, reductive amination of aldehydes and ketones, and reductive methylation of amines.
- Firouzabadi, Habib,Iranpoor, Nasser,Alinezhad, Heshmatollah
-
p. 143 - 151
(2007/10/03)
-
- Model compounds study on the network structure of polybenzoxazines
-
The FT-IR and 1H NMR spectra of model dimers, having different molecular sizes and pKa, are investigated in order to understand the differences in the hydrogen-bonded network structures of polybenzoxazines. The correlation between the -OH...N intramolecular hydrogen-bonding interaction and benzoxazine functional groups in the asymmetric dimers is investigated by 1H NMR spectra. While the FT-IR spectra of the model dimers indicate that the nature of hydrogen bonding is closely related to the basicity of the amine constituent, the spectra of the corresponding polymers suggest the existence of different hydrogen-bonding interactions. The existence of phenolic linkage formation and the stability of the Mannich base structure during polymerization are investigated by a dimerization reaction. It is demonstrated that benzoxazines based upon extremely bulky amines do not develop desirable properties due to the extensive degradation process.
- Kim, Ho-Dong,Ishida, Hatsuo
-
p. 8320 - 8329
(2007/10/03)
-
- Chemoselective reductive amination of aldehydes and ketones by dibutylchlorotin hydride-HMPA complex
-
Reductive amination of various aldehydes and ketones has been performed effectively by pentacoordinate chloro-substituted tin hydride complex, Bu2SnClH-HMPA. The tin reagent worked particularly well for the case using weakly basic aromatic amines as starting substrates. Stoichiometric amounts of a substrate and a reducing agent were adequate for the reaction. The Sn-Cl bond in the complex plays an important role for both steps of imine formation and subsequent reduction. Highly chemoselective reduction of carbonyls could be achieved regardless of other functionalities such as halogen, carbon- carbon double bond and hydroxyl groups in the starting carbonyls and amines.
- Suwa, Toshihiro,Sugiyama, Erika,Shibata, Ikuya,Baba, Akio
-
p. 789 - 800
(2007/10/03)
-
- Chemoselective debenzylation of N-benzyl tertiary amines with ceric ammonium nitrate
-
Treatment of a range of N-benzyl tertiary amines with aqueous eerie ammonium nitrate results in N-debenzylation to afford the corresponding secondary amine. Chemoselective mono-W-debenzylation of N-benzyl tertiary amines is shown to occur in the presence of N-benzyl amides, O-benzyl ethers, O-benzyl esters, O-benzyl phenolates and 5-benzyl ethers. The Royal Society of Chemistry 2000.
- Bull, Steven D.,Davies, Stephen G.,Fenton, Carry,Mulvaney, Andrew W.,Shyam Prasad,Smith, Andrew D.
-
p. 3765 - 3774
(2007/10/03)
-
- Reductive amination promoted by tributyltin hydride
-
Reductive amination of carbonyl compounds with primary and secondary ammonium salts was performed by tributyltin hydride in DMF solvent at room temperature. A variety of secondary and tertiary amines including sterically hindered ones could be synthesized in one-pot procedure. No side reaction such as the reduction of starting carbonyl or overalkylation was detected.
- Suwa, Toshihiro,Sugiyama, Erika,Shibata, Ikuya,Baba, Akio
-
p. 556 - 558
(2007/10/03)
-
- Gas-phase selective N-alkylation of amines with alcohols over γ- alumina
-
Gas-phase conditions were successfully used for fine chemistry, in the N-alkylation of amines with alcohols as alkylating agents and γ-alumina as a catalyst. The method is also suitable for chiral compounds.
- Valot, Frederic,Fache, Fabienne,Jacquot, Roland,Spagnol, Michel,Lemaire, Marc
-
p. 3689 - 3592
(2007/10/03)
-
- A Facile Synthesis of Trifluoromethylamines by Oxidative Desulfurization-Fluorination of Dithiocarbamates
-
Trifluoromethylamines are easily synthesized from dithiocarbamates by a reagent system consisting of tetrabutylammonium dihydrogentrifluoride and an N-halo imide under mild conditions. When this reaction was applied to dithiocarbamates ArN(R)CS2Me at higher temperatures, the trifluoromethylation was accompanied by halogen substitution at the p-position of the Ar group. The synthesis of trifluoromethyl-substituted adenosine is also described.
- Kanie, Kiyoshi,Mizuno, Katsuya,Kuroboshi, Manabu,Hiyama, Tamejiro
-
p. 1973 - 1991
(2007/10/03)
-
- Reduction of imines via titanium-catalyzed hydromagnesation
-
We have recently discovered that imines can be reduced to amines via a titanium catalyzed hydromagnesation reaction. These reactions employ n-BuMgCl (1.2 eq) as the stoichiometric reducing agent and Cp2TiCl2 (3-5 mol%) as a catalyst. Reactions are run under nitrogen at ambient temperature and pressure. For most aldimine and cyclic ketimine substrates amine products are obtained in yields ranging from 69-94%. The reaction is not tolerant of bulky nitrogen substituents or primary enolizable protons on the imine substrate.
- Amin, Sk. Rasidul,Crowe, William E.
-
p. 7487 - 7490
(2007/10/03)
-
- Synthesis of 4-N,N-dialkylaminoethyl-2-indolones as potential dopamine agonists
-
A set of fourteen 4-ethyl>-2-indolone analogues of dopamine were synthesized in 15 steps and evaluated for their affinities towards the D2 receptor using sulpiride or spiperone as radioligands.Six analogues displayed D2 agonist activities comparable (Ki = 450 - 650 nM) to Ropinirole or SK and F 101468.The functionalized amino side chain introduced in the 4-position can be used to modulate the lipophlicity of the analogues without significantly affecting D2 activity. - Keywords: lactam; indolone; rigid dopamine analogue; D2 receptor binding
- Namil, A.,Benoit-Guyod, M.,Leclerc, G.
-
p. 973 - 982
(2007/10/03)
-