10316-00-4Relevant articles and documents
The different, but interesting behaviors of benzyl systems in the Willgerodt-Kindler reaction under solvent-free conditions
Aghapoor, Kioumars,Darabi, Hossein Reza,Tabar-Heydar, Kourosh
, p. 1183 - 1187 (2002)
On the benzyl system, bearing various functional groups, have been carried out the Willgerodt-Kindler reaction to obtain thiobenzmorpholide (1). The reactions, under solvent-free conditions, were performed in both classical (reflux, room temperature) and
On the non-classical course of Polonowski reactions of N-benzylmorpholine- N-oxide (NBnMO)
Rosenau, Thomas,Schmid, Peter,Kosma, Paul
, p. 3483 - 3487 (2005)
The Polonowski reaction of NBnMO (4) afforded tropone (10) and the novel isoindole 11 besides the expected products benzaldehyde and acetmorpholide, in a temperature-dependent ratio. The reaction proceeded via two primary carbenium-iminium ion intermediates, an exo-centered species 5 which underwent a benzylium-tropylium type rearrangement, and a ring-centered species 6, which reacted further to isoindole 11 by intramolecular electrophilic substitution. The experimental findings were in good agreement with DFT computational data.
Cesium carbonate-catalyzed reduction of amides with hydrosilanes
Xie, Weilong,Zhao, Mengdi,Cui, Chunming
, p. 7440 - 7444 (2013)
Cesium carbonate has been found to be an effective catalyst for the reduction of tertiary carboxamides with the simple, commercially available PhSiH3 under solvent-free conditions. The catalytic system can effectively reduce a range of amides under relatively mild conditions (from room temperature to 80 C) to yield the corresponding amines in good to excellent yields (71-100%) and thus has the potential for practical applications.
Reductive amination of carbonyl compounds over silica supported palladium exchanged molybdophosphoric acid catalysts
Srivani,Prasad, P. S. Sai,Lingaiah
, p. 389 - 396 (2012)
Palladium exchanged molybdophosphoric acid supported on silica is reported as a highly effective catalyst for direct reductive amination of carbonyl compounds. The catalysts are characterized by X-ray diffraction and FT-infrared spectroscopy. The characterization results support the existence of Keggin ion of heteropoly molybdate on silica. The catalyst is facile, water tolerable and environmentally benign for reductive amination. A variety of secondary and tertiary amines can be synthesized over this catalyst in excellent yields under mild reaction conditions. A plausible reaction mechanism is proposed for the reductive amination of carbonyl compounds over this catalyst.
Palladium on activated carbon catalyzed reductive amination of aldehydes and ketones by triethylsilane
Mirza-Aghayan, Maryam,Tavana, Mahdieh Molaee,Rahimifard, Mahshid,Boukherroub, Rabah
, p. 113 - 115 (2014)
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.
Copper-catalyzed oxygen atom transfer of N-oxides leading to a facile deoxygenation procedure applicable to both heterocyclic and amine N-oxides
Jeong, Jisu,Lee, Donggun,Chang, Sukbok
, p. 7035 - 7038 (2015)
Deoxygenation of various types of N-oxides including both heterocyclic and alkyl(aryl)amine derivatives has successfully been developed by the copper-catalyzed oxygen atom transfer using diazo compounds as the oxygen acceptor. The reaction proceeds smoothly over a broad range of substrates with excellent functional group tolerance under mild conditions. This journal is
N-Alkylation and N,C-Dialkylation of Amines with Alcohols in the Presence of Ruthenium Catalysts with Chelating N-Heterocyclic Carbene Ligands
?ahin, Zeynel,Gürbüz, Nevin,?zdemir, Ismail,?ahin, Onur,Büyükgüng?r, Orhan,Achard, Mathieu,Bruneau, Christian
, p. 2296 - 2304 (2015)
A series of new benzimidazolium salts and ruthenium(II) complexes containing chelating N-heterocyclic carbenes (NHCs) functionalized with a benzylic group and an acetal group were prepared. All of the synthesized compounds were characterized by elemental analysis and NMR spectroscopy, and the molecular structures of 2c and 2d were determined by X-ray crystallography. All of the complexes were tested in the alkylation of cyclic amine derivatives with alcohols and showed excellent activity in this reaction. Cyclic amines were alkylated with primary and heteroaromatic alcohols. The Ru-NHC complexes also catalyzed N,C3-dialkylation of cyclic amines. (Chemical Equation Presented).
Ruthenium-catalysed synthesis of tertiary amines from alcohols
Hamid, M. Haniti S.A.,Williams, Jonathan M.J.
, p. 8263 - 8265 (2007)
Secondary amines have been converted into tertiary amines by reactions with primary alcohols. A catalytic system of [Ru(cymene)Cl2]2 with dppf has been shown to be effective for this transformation for a range of primary alcohols and secondary amines. The methodology has been applied to the one pot synthesis of Piribedil and other piperazine and morpholine-containing products.
Reductive amination of aldehydes and ketones under heterogeneous and solvent-free conditions using sodium-borohydride and silica-gel-supported sulfuric acid
Alinezhad, Heshmatollah,Tajbakhsh, Mahmood,Zare, Mahboobeh
, p. 2907 - 2916 (2009)
A regioselective and convenient procedure for preparation of amines by reductive amination of aldehydes and ketones using sodium borohydride in the presence of sulfuric acid supported on silica gel as an active, inexpensive, and recoverable catalyst under heterogeneous and solvent-free conditions at room temperature is described.
REACTIVITY OF PHENOLATES IN THE REACTION WITH p-NITROPHENYL ACETATE
Teitel'baum, A. B.,Ryzhkina, I. S.,Kudryavtseva, L. A.,Bel'skii, V. E.,Ivanov, B. E.
, p. 918 - 922 (1983)
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Reductive amination of aldehydes and ketones using sodium borohydride in the presence of silica chloride under solvent-free conditions
Alinezhad, Heshmatollah,Tajbakhsh, Mahmood,Hamidi, Neda
, p. 47 - 50 (2010)
A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described. A variety of aliphatic and aromatic aldehydes, ketones and amines when mixed with NaBH4/silica chloride at room temperature, afforded excellent yield of the corresponding amines.
Reductive amination using a combination of CaH2 and noble metal
Guyon, Carole,Da Silva, Eric,Lafon, Romain,Mtay, Estelle,Lemaire, Marc
, p. 2292 - 2298 (2015)
Amines were prepared by a reductive amination reaction in the presence of calcium hydride and Pt/C. The in situ formation of water seems to be the key to activate CaH2 to reduce the intermediate imine.
Copper-Catalyzed Electrophilic Amination of Diorganozinc Reagents
Berman, Ashley M.,Johnson, Jeffrey S.
, p. 5680 - 5681 (2004)
The copper-catalyzed electrophilic amination of diorganozinc reagents employing O-acyl N,N-dialkyl hydroxylamine derivatives as aminating agents is described. This reaction offers a general method for the preparation of tertiary amines in high yields and is noteworthy for its convenience both in terms of reaction conditions employed (room temperature, ≤1 h) and ease of product isolation (acid/base extractive workup). Copyright
Direct reductive amination of carbonyl compounds using sodium borohydride-silica chloride
Alinezhad, Heshmatollah,Tajbakhsh, Mahmood,Hamidi, Neda
, p. 307 - 312 (2010)
A simple and convenient procedure for reductive amination of aldehydes and ketones using sodium borohydride in the presence of silica chloride as an active, inexpensive, recoverable, and recyclable catalyst is described. The reactions were carried out with equimolar amounts of amine and carbonyl compound using silica chloride-sodium borohydride in THF at room temperature TUeBITAK.
Base-promoted N-alkylation using formamides as the N-sources in neat water
Chen, Wen-Xin,Zhang, Cai-Yun,Shao, Li-Xiong
, p. 880 - 885 (2014)
An efficient catalyst-free, alternative method for the C-N bond formation reaction of alkyl electrophiles using formamides as the N-sources was achieved under mild conditions. The reaction possesses the advantages of a broad range of substrates scope and wide functional group tolerance. It should also be noted that this process was performed using the environmentally benign water as the sole solvent, and high yield can also be achieved in ten-gram scale.
Overcoming solid handling issues in continuous flow substitution reactions through ionic liquid formation
Kashani, Saeed,Sullivan, Ryan J.,Andersen, Mads,Newman, Stephen G.
, p. 1748 - 1753 (2018)
Substitutions such as acylations, arylations, and alkylations are some of the most commonly run reactions for building complex molecules. However, the requirement of a stoichiometric base to scavange acid by-products creates significant challenges when operating in continuous flow due to solid handling issues associated with precipitating base·HX salts. We present a general and simple strategy to overcome these solid handling issues through the use of acid scavenging organic bases that generate low- to moderate-melting ionic liquids upon protonation. The application of these bases towards the most commonly run substitutions are demonstrated, enabling reactions to be run in flow without requiring additional equipment, specific solvents, or dilute reaction conditions to prevent clogging.
A practical catalytic reductive amination of carboxylic acids
Andrews, Keith G.,Denton, Ross M.,Hirst, David J.,Stoll, Emma L.,Tongue, Thomas,Valette, Damien
, p. 9494 - 9500 (2020)
We report reductive alkylation reactions of amines using carboxylic acids as nominal electrophiles. The two-step reaction exploits the dual reactivity of phenylsilane and involves a silane-mediated amidation followed by a Zn(OAc)2-catalyzed amide reduction. The reaction is applicable to a wide range of amines and carboxylic acids and has been demonstrated on a large scale (305 mmol of amine). The rate differential between the reduction of tertiary and secondary amide intermediates is exemplified in a convergent synthesis of the antiretroviral medicine maraviroc. Mechanistic studies demonstrate that a residual 0.5 equivalents of carboxylic acid from the amidation step is responsible for the generation of silane reductants with augmented reactivity, which allow secondary amides, previously unreactive in zinc/phenylsilane systems, to be reduced.
Synthesis of substituted amines and isoindolinones: Catalytic reductive amination using abundantly available AlCl3/PMHS
Kumar, Vishal,Sharma, Sushila,Sharma, Upendra,Singh, Bikram,Kumar, Neeraj
, p. 3410 - 3414 (2012)
AlCl3 has been employed for highly chemoselective reductive amination of carbonyl compounds in ethanol using polymethylhydrosiloxane as an inexpensive, stable and safe reducing agent without an inert atmosphere. A large range of functional groups such as nitro, carboxylic acid, acetyl, nitrile, halogen, methoxy, alkene and heterocycles were well tolerated. AlCl3 also catalyzed tandem amination-amidation of 2-carboxybenzaldehyde with different amines to afford N-substituted isoindolinones. The catalyst can be recycled at least three times without any significant effect on activity and selectivity.
Synthesis and applications of Fe3O4- diisopropylaminoacetamide as a versatile and reusable magnetic nanoparticle supported N,N-diisopropylethylamine equivalent
Rattanaburi, Parintip,Khumraksa, Bannarak,Pattarawarapan, Mookda
, p. 2689 - 2693 (2012)
A magnetic nanoparticle supported N,N-diisopropylaminoacetamide (Fe 3O4-DIPA) was developed for application as a magnetic recoverable, and reusable N,N-diisopropylethylamine equivalent. The Fe 3O4 nanoparticles were coated with a silica layer using the sol-gel method, followed by surface modification with 3- aminopropyltriethoxysilane. Subsequent acylation with chloroacetyl chloride and chlorine displacement with diisopropylamine afforded Fe3O 4-DIPA in 90% yield with a loading of 0.96 mmol/g. The applicability of Fe3O4-DIPA was demonstrated in the synthesis of amine derivatives cv sulfonation, acylation, and N-alkylation reactions. The desired products were obtained in excellent yields and purities after scavenging the residual starting amines by treatment with silica-supported dichlorotriazine. Fe3O4-DIPA was readily recovered by separation using a magnet and could be reused several times without significant loss of reactivity.
Benzimidazolin-2-ylidene N-heterocyclic carbene complexes of ruthenium as a simple catalyst for the N-alkylation of amines using alcohols and diols
Shan, Siah Pei,Xiaoke, Xie,Gnanaprakasam, Boopathy,Dang, Tuan Thanh,Ramalingam, Balamurugan,Huynh, Han Vinh,Seayad, Abdul Majeed
, p. 4434 - 4442 (2015)
Simple air and moisture stable ruthenium complexes 1-3 and 3a were synthesized from readily available benzannulated N-heterocyclic carbene ligands (bimy = benzimidazolin-2-ylidene). These complexes were found to be efficient catalysts for the alkylation of amines using alcohols as alkylating agents. Catalysts 1, 2 and 3a gave excellent yields of up to 99% for the alkylation of various amines using benzylic and aliphatic alcohols at 130 °C for 18 h under solventless conditions. Catalyst 3a bearing both phosphine and carbene ligands gave excellent yields of up to 98% for the synthesis of heterocyclic amines by double alkylation of primary amines using linear diols. The practical utility of these catalysts was demonstrated for the synthesis of pharmaceutically important amines in a more environmentally benign way under solventless conditions.
SiO2-Cu2O: An efficient and recyclable heterogeneous catalyst for N-benzylation of primary and secondary amines
Gupta, Manjulla,Paul, Satya,Gupta, Rajive
, p. 444 - 450 (2014)
A mild, effective, and selective procedure is reported for the mono N-benzylation and N,N-dibenzylation of primary amines as well as mono N-benzylation of secondary amines using silica-supported copper(I) oxide in water. The silica-supported Cu2O was generated in situ by the reaction of Fehling solution and glucose at 100 C onto activated silica. The catalyst was filtered, washed with water, and oven-dried, and was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, and atomic absorption spectroscopy. The prepared Cu2O-SiO2 was found to be thermally stable up to 325 C. The copper was uniformly distributed onto the surface of the silica, and the mean particle diameter was 7 nm. The catalyst served as a selective heterogenous catalyst for the N-benzylation of primary and secondary amines. The catalyst is recyclable and was used effectively upto fifth run without a significant loss of catalytic activity. Various reaction solvents including water, acetonitrile, and toluene were screened for N-benzylation of amines, and the success of the aqueous system highlights the low environmental impact of the procedure.
Mechanochemical Nucleophilic Substitution of Alcohols via Isouronium Intermediates**
Dalidovich, Tatsiana,Nallaparaju, Jagadeesh Varma,Shalima, Tatsiana,Aav, Riina,Kananovich, Dzmitry G.
, (2022/01/26)
An expansion of the solvent-free synthetic toolbox is essential for advances in the sustainable chemical industry. Mechanochemical reactions offer a superior safety profile and reduced amount of waste compared to conventional solvent-based synthesis. Here
Pd(II)-Mediated C?H Activation for Cysteine Bioconjugation
Frost, Christopher G.,Kociok-K?hn, Gabriele,Lubben, Anneke T.,Reeksting, Shaun B.,Tilden, James A. R.
supporting information, (2022/01/19)
Selective bioconjugation remains a significant challenge for the synthetic chemist due to the stringent reaction conditions required by biomolecules coupled with their high degree of functionality. The current trailblazer of transition-metal mediated bioconjugation chemistry involves the use of Pd(II) complexes prepared via an oxidative addition process. Herein, the preparation of Pd(II) complexes for cysteine bioconjugation via a facile C?H activation process is reported. These complexes show bioconjugation efficiency competitive with what is seen in the current literature, with a user-friendly synthesis, common Pd(II) sources, and a more cost-effective ligand. Furthermore, these complexes need not be isolated, and still achieve high conversion efficiency and selectivity of a model peptide. These complexes also demonstrate the ability to selectively arylate a single surface cysteine residue on a model protein substrate, further demonstrating their utility.
Transition-Metal-Free, General Construction of Thioamides from Chlorohydrocarbon, Amide and Elemental Sulfur
Chen, Xinzhi,Ge, Xin,Jin, Hao,Qian, Chao,Zhou, Shaodong
supporting information, p. 3403 - 3406 (2021/06/25)
A general method for one-pot synthesis of thioamides is developed through a three-component reaction involving chlorohydrocarbon, amide and elemental sulfur. Such a strategy does not only avoid residual transition metal in the product but also prevent the generation of C?N coupling by-product. The latter is prone to be generated when alkane halide and amine are present. With the protocol proposed in this work, both alkyl and aryl thioamides can be obtained in moderate to excellent yields with a high tolerance of various functional groups. External oxidants are not required in the reaction. In addition, the reaction mechanisms are addressed using a combination of controlling experiments and quantum chemical calculations.
