15402-84-3Relevant academic research and scientific papers
Markovnikov Wacker-Tsuji Oxidation of Allyl(hetero)arenes and Application in a One-Pot Photo-Metal-Biocatalytic Approach to Enantioenriched Amines and Alcohols
Albarrán-Velo, Jesús,Gotor-Fernández, Vicente,Lavandera, Iván
, p. 4096 - 4108 (2021/08/19)
The Wacker-Tsuji aerobic oxidation of various allyl(hetero)arenes under photocatalytic conditions to form the corresponding methyl ketones is presented. By using a palladium complex [PdCl2(MeCN)2] and the photosensitizer [Acr-Mes]ClO4 in aqueous medium and at room temperature, and by simple irradiation with blue led light, the desired carbonyl compounds were synthesized with high conversions (>80%) and excellent selectivities (>90%). The key process was the transient formation of Pd nanoparticles that can activate oxygen, thus recycling the Pd(II) species necessary in the Wacker oxidative reaction. While light irradiation was strictly mandatory, the addition of the photocatalyst improved the reaction selectivity, due to the formation of the starting allyl(hetero)arene from some of the obtained by-products, thus entering back in the Wacker-Tsuji catalytic cycle. Once optimized, the oxidation reaction was combined in a one-pot two-step sequential protocol with an enzymatic transformation. Depending on the biocatalyst employed, i. e. an amine transaminase or an alcohol dehydrogenase, the corresponding (R)- and (S)-1-arylpropan-2-amines or 1-arylpropan-2-ols, respectively, could be synthesized in most cases with high yields (>70%) and in enantiopure form. Finally, an application of this photo-metal-biocatalytic strategy has been demonstrated in order to get access in a straightforward manner to selegiline, an anti-Parkinson drug. (Figure presented.).
The Synthesis of Primary Amines through Reductive Amination Employing an Iron Catalyst
B?umler, Christoph,Bauer, Christof,Kempe, Rhett
, p. 3110 - 3114 (2020/06/01)
The reductive amination of ketones and aldehydes by ammonia is a highly attractive method for the synthesis of primary amines. The use of catalysts, especially reusable catalysts, based on earth-abundant metals is similarly appealing. Here, the iron-catalyzed synthesis of primary amines through reductive amination was realized. A broad scope and a very good tolerance of functional groups were observed. Ketones, including purely aliphatic ones, aryl–alkyl, dialkyl, and heterocyclic, as well as aldehydes could be converted smoothly into their corresponding primary amines. In addition, the amination of pharmaceuticals, bioactive compounds, and natural products was demonstrated. Many functional groups, such as hydroxy, methoxy, dioxol, sulfonyl, and boronate ester substituents, were tolerated. The catalyst is easy to handle, selective, and reusable and ammonia dissolved in water could be employed as the nitrogen source. The key is the use of a specific Fe complex for the catalyst synthesis and an N-doped SiC material as catalyst support.
Stereoselective Synthesis of 1-Arylpropan-2-amines from Allylbenzenes through a Wacker-Tsuji Oxidation-Biotransamination Sequential Process
González-Martínez, Daniel,Gotor, Vicente,Gotor-Fernández, Vicente
, p. 2582 - 2593 (2019/05/15)
Herein, a sequential and selective chemoenzymatic approach is described involving the metal-catalysed Wacker-Tsuji oxidation of allylbenzenes followed by the amine transaminase-catalysed biotransamination of the resulting 1-arylpropan-2-ones. Thus, a series of nine optically active 1-arylpropan-2-amines were obtained with good to very high conversions (74–92%) and excellent selectivities (>99% enantiomeric excess) in aqueous medium. The Wacker-Tsuji reaction has been exhaustively optimised searching for compatible conditions with the biotransamination experiments, using palladium(II) complexes as catalysts and iron(III) salts as terminal oxidants in aqueous media. The compatibility of palladium/iron systems for the chemical oxidation with commercially available and made in house amine transaminases was analysed, finding ideal conditions for the development of a general and stereoselective cascade sequence. Depending on the selectivity displayed by selected amine transaminase, it was possible to produce both 1-arylpropan-2-amines enantiomers under mild reaction conditions, compounds that present therapeutic properties or can be employed as synthetic intermediates of chiral drugs from the amphetamine family. (Figure presented.).
MOF-derived cobalt nanoparticles catalyze a general synthesis of amines
Jagadeesh, Rajenahally V.,Murugesan, Kathiravan,Alshammari, Ahmad S.,Neumann, Helfried,Pohl, Marga-Martina,Radnik, J?rg,Beller, Matthias
, p. 326 - 332 (2017/09/28)
The development of base metal catalysts for the synthesis of pharmaceutically relevant compounds remains an important goal of chemical research. Here, we report that cobalt nanoparticles encapsulated by a graphitic shell are broadly effective reductive amination catalysts. Their convenient and practical preparation entailed template assembly of cobaltdiamine- dicarboxylic acid metal organic frameworks on carbon and subsequent pyrolysis under inert atmosphere.The resulting stable and reusable catalysts were active for synthesis of primary, secondary, tertiary, and N-methylamines (more than 140 examples).The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, or nitro compounds, and molecular hydrogen under industrially viable and scalable conditions, offering cost-effective access to numerous amines, amino acid derivatives, and more complex drug targets.
Nucleophilic Amination of Methoxy Arenes Promoted by a Sodium Hydride/Iodide Composite
Kaga, Atsushi,Hayashi, Hirohito,Hakamata, Hiroyuki,Oi, Miku,Uchiyama, Masanobu,Takita, Ryo,Chiba, Shunsuke
supporting information, p. 11807 - 11811 (2017/09/20)
A method for the nucleophilic amination of methoxy arenes was established by using sodium hydride (NaH) in the presence of lithium iodide (LiI). This method offers an efficient route to benzannulated nitrogen heterocycles. Mechanistic studies showed that the reaction proceeds through an unusual concerted nucleophilic aromatic substitution.
Ligand-Enabled meta-Selective C-H Arylation of Nosyl-Protected Phenethylamines, Benzylamines, and 2-Aryl Anilines
Ding, Qiuping,Ye, Shengqing,Cheng, Guolin,Wang, Peng,Farmer, Marcus E.,Yu, Jin-Quan
supporting information, p. 417 - 425 (2017/05/16)
A Pd-catalyzed, meta-selective C-H arylation of nosyl-protected phenethylamines and benzylamines is disclosed using a combination of norbornene and pyridine-based ligands. Subjecting nosyl protected 2-aryl anilines to this protocol led to meta-C - H arylation at the remote aryl ring. A diverse range of aryl iodides are tolerated in this reaction, along with select heteroaryl iodides. Select aryl bromides bearing ortho-coordinating groups can also be utilized as effective coupling partners in this reaction. The use of pyridine ligands has allowed the palladium loading to be reduced to 2.5 mol %. Furthermore, a catalytic amount of 2-norbomene (20 mol %) to mediate this meta-C - H activation process is demonstrated for the first time. Utilization of a common protecting group as the directing group for meta-C-H activation of amines is an important feature of this reaction in terms of practical applications.
Leuckart-Wallach Route Toward Isocyanides and Some Applications
Neochoritis, Constantinos G.,Zarganes-Tzitzikas, Tryfon,Stotani, Silvia,D?mling, Adrian,Herdtweck, Eberhardt,Khoury, Kareem,D?mling, Alexander
, p. 493 - 499 (2015/09/22)
Isocyanide-based multicomponent reactions (IMCR) are among the most important chemical reactions to efficiently generate molecular diversity and have found widespread use in industry and academia. Generally, isocyanides are synthesized in 1-2 steps starting from primary amines. Here, we provide experimental detail on an alternative approach toward formamides and, thus, isocyanides via the Leuckart-Wallach reaction in an improved variation. The resulting >50 synthesized and characterized formamides are useful starting materials for IMCR, as well as other chemistries. The advantage of using the Leuckart-Wallach pathway to formamides and isocyanides is the lower price, on average, of the starting materials, as well as their differential and complementary structural diversity, as compared to the primary amine pathway.
Synthesis and characterization of hydroxylated mesocarb metabolites for doping control
Vahermo, Mikko,Suominen, Tina,Leinonen, Antti,Yli-Kauhaluoma, Jari
scheme or table, p. 201 - 209 (2009/05/09)
The synthesis and method of analysis of hydroxylated mesocarb metabolites are described. Six potential hydroxylated mesocarb metabolites were prepared, characterized, and compared with the mesocarb metabolites synthesized enzymatically in vitro using human liver proteins and also compared with metabolites extracted from human urine after oral administration of mesocarb. p-Hydroxymesocarb was the most prevalent metabolite (conjugated and non-conjugated) observed. With respect to doping analysis, synthesis of p-hydroxymesocarb, the main urinary metabolite of mesocarb, and its availability as a reference material is important.
CAL-B-catalyzed resolution of some pharmacologically interesting β-substituted isopropylamines
Gonzalez-Sabin, Javier,Gotor, Vicente,Rebolledo, Francisca
, p. 1315 - 1320 (2007/10/03)
Some pharmacologically active amines such as amphetamine, the isomeric o-, m- and p-methoxyamphetamines, 4-phenylbutan-2-amine and mexiletine, as well as their corresponding acetamides, have been prepared in high yields and with very high enantiomeric excesses. The method consists of the Candida antarctica lipase B (CAL-B)-mediated enantioselective acetylation of racemic amines using ethyl acetate as solvent and acyl donor. The enzyme follows Kazlauskas' rule with all amines, (R)-amides being obtained as the major enantiomer in all cases. From the conversion values measured for both enantiomers, it can be deduced that the size of the substituents attached to the stereocenter is responsible for the enantioselectivity and rate of some of these reactions.
Photoinduced nucleophilic addition of ammonia and alkylamines to methoxy-substituted styrene derivatives
Yamashita,Yamashita, Toshiaki,Yasuda,Yasuda, Masahide,Isami,Isami, Toshihiro,Tanabe,Tanabe, Kimiko,Shima,Shima, Kensuke
, p. 9275 - 9286 (2007/10/02)
The photoamination of trans-1-arylpropenes (aryl = 2-methoxyphenyl), (1), 3-methoxyphenyl (2) 3,4-dimethoxyphenyl (3), and 4-methoxyphenyl (4) with NH3, i-PrNH2, and t-BuNH2 (RNH2), in the presence of p-dicyanobenzene (p-DCB) gave 2-alkylamino-1 arylpropanes (9) and/or 2-alkylamino-1-aryl-1-(4-cyanophenyl)propanes (10). The photoaminations of 1,2-dihydro-7-methoxynaphthalenes (6-8) with RNH2 in the presence of p-DCB gave mainly 2-alkylamino-1-(4-cyanophenyl)-6-methoxy-1,2,3,4-tetrahydronaphthalene s (13). The photoamination of trans-1-(3,5-dimethoxyphenyl)propene (5) with i-PrNH2 occurred at aromatic ring to give trans-1-(2-isopropylamino-3,5-dimethoxyphenyl)propene (11). The photoaminations of 1-4 and 6-8 with NH3 in the presence of m-dicyanobenzene gave the aminated products without incorporation of cyanophenyl group. Furthermore, the addition of 1,3,5-triphenylbenzene and m-terphenyl for these reactions improved the yields of the photoaminated products.
