- Direct reductive amination of ketones with ammonium salt catalysed by Cp*Ir(iii) complexes bearing an amidato ligand
-
A series of half-sandwich Ir(iii) complexes1-6bearing an amidato bidentate ligand were conveniently synthesized and applied to the catalytic Leuckart-Wallach reaction to produce racemic α-chiral primary amines. With 0.1 mol% of complex1, a broad range of ketones, including aryl ketones, dialkyl ketones, cyclic ketones, α-keto acids, α-keto esters and diketones, could be transformed to their corresponding primary amines with moderate to excellent yields (40%-95%). Asymmetric transformation was also attempted with chiral Ir complexes3-6, and 16% ee of the desired primary amine was obtained. Despite the unsatisfactory enantio-control achieved so far, the current exploration might stimulate more efforts towards the discovery of better chiral catalysts for this challenging but important transformation.
- Dai, Zengjin,Pan, Ying-Min,Wang, Shou-Guo,Yin, Qin,Zhang, Xumu
-
supporting information
p. 8934 - 8939
(2021/11/04)
-
- Air Stable Iridium Catalysts for Direct Reductive Amination of Ketones
-
Half-sandwich iridium complexes bearing bidentate urea-phosphorus ligands were found to catalyze the direct reductive amination of aromatic and aliphatic ketones under mild conditions at 0.5 mol % loading with high selectivity towards primary amines. One of the complexes was found to be active in both the Leuckart–Wallach (NH4CO2H) type reaction as well as in the hydrogenative (H2/NH4AcO) reductive amination. The protocol with ammonium formate does not require an inert atmosphere, dry solvents, as well as additives and in contrast to previous reports takes place in hexafluoroisopropanol (HFIP) instead of methanol. Applying NH4CO2D or D2 resulted in a high degree of deuterium incorporation into the primary amine α-position.
- Polishchuk, Iuliia,Sklyaruk, Jan,Lebedev, Yury,Rueping, Magnus
-
supporting information
p. 5919 - 5922
(2021/03/08)
-
- Iterative Alanine Scanning Mutagenesis Confers Aromatic Ketone Specificity and Activity of L-Amine Dehydrogenases
-
Direct reductive amination of prochiral ketones catalyzed by amine dehydrogenases is attractive in the synthesis of active pharmaceutical ingredients. Here, we report the protein engineering of L-Bacillus cereus amine dehydrogenase to allow reactivity on synthetically useful aromatic ketone substrates using an iterative, multiple-site alanine scanning mutagenesis approach. Mutagenesis libraries based on molecular docking, iterative alanine scanning, and double-proximity filter approach significantly expand the scope of active pharmaceutical ingredients relevant building blocks. The eventual quintuple mutant (A115G/T136A/L42A/V296A/V293A) showed reactivity toward aromatic ketones 12 a (5-phenyl-pentan-2-one) and 13 a (6-phenyl-hexan-2-one), which have not been reported to serve as targets of reductive amination by currently available amine dehydrogenases. Docking simulation and tunnel analysis provided valuable insights into the source of the acquired specificity and activity.
- Mu, Xiaoqing,Wu, Tao,Mao, Yong,Zhao, Yilei,Xu, Yan,Nie, Yao
-
p. 5243 - 5253
(2021/11/16)
-
- Enzymatic Primary Amination of Benzylic and Allylic C(sp3)-H Bonds
-
Aliphatic primary amines are prevalent in natural products, pharmaceuticals, and functional materials. While a plethora of processes are reported for their synthesis, methods that directly install a free amine group into C(sp3)-H bonds remain unprecedented. Here, we report a set of new-to-nature enzymes that catalyze the direct primary amination of C(sp3)-H bonds with excellent chemo-, regio-, and enantioselectivity, using a readily available hydroxylamine derivative as the nitrogen source. Directed evolution of genetically encoded cytochrome P411 enzymes (P450s whose Cys axial ligand to the heme iron has been replaced with Ser) generated variants that selectively functionalize benzylic and allylic C-H bonds, affording a broad scope of enantioenriched primary amines. This biocatalytic process is efficient and selective (up to 3930 TTN and 96percent ee), and can be performed on preparative scale.
- Jia, Zhi-Jun,Gao, Shilong,Arnold, Frances H.
-
supporting information
p. 10279 - 10283
(2020/07/27)
-
- Thermal and Mechanical Stability of Immobilized Candida antarctica Lipase B: an Approximation to Mechanochemical Energetics in Enzyme Catalysis.
-
Very recently, several successful enzymatic processes performed with mechanical activation have been disclosed; that is, despite the mechanical stress caused by High-Speed Ball-Milling, immobilized enzymes can retain activity. In the present study, the effect of thermal and mechanical stress was examined as potential inducers of enzymatic denaturation, when using either free, immobilized, or ground immobilized enzyme. The recorded observations show a remarkable stability of ground immobilized enzyme. Moreover, ground biocatalyst turns out to exhibit an increase of one order of magnitude in the efficiency of the catalytic process, maintaining excellent enantiodiscrimination, without significant activity loss even after four milling cycles. These observations rule out enzyme inactivation as direct consequence of the milling process. Additionally, boosted enzyme efficiency was used to optimize a relatively inefficient chiral amine resolution reaction, achieving a 25 % faster biotransformation (in 45 min) and yielding essentially enantiopure products (ee>99%, E>500).
- Pérez-Venegas, Mario,Tellez-Cruz, Miriam M.,Solorza-Feria, Omar,López-Munguía, Agustín,Castillo, Edmundo,Juaristi, Eusebio
-
p. 803 - 811
(2019/12/11)
-
- HETEROCYCLIC COMPOUNDS AS MUTANT IDH INHIBITORS
-
The present disclosure relates generally to compounds useful in treatment of conditions associated with mutant isocitrate dehydrogenase (mt-IDH), particularly mutant IDH1 enzymes. Specifically, the present invention discloses compound of formula (IA), which exhibits inhibitory activity against mutant IDH1 enzymes. Method of treating conditions associated with excessive activity of mutant IDH1 enzymes with such compound is disclosed. Uses thereof, pharmaceutical composition, and kits are also disclosed.
- -
-
Paragraph 0265-0266
(2020/07/16)
-
- Rh(III)-catalyzed synthesis of isoquinolines using the N-Cl bond of N-chloroimines as an internal oxidant
-
The Rh(III)-catalyzed coupling of N-chloroimines with alkynes for the efficient synthesis of isoquinolines is reported. This represents the first use of the N-Cl bond of N-chloroimines as an internal oxidant for construction of the isoquinoline skeleton. The synthesis features atom and step economy, a green solvent (EtOH), mild reaction conditions, and a broad substrate scope.
- Chu, Benfa,Fang, Lili,Guo, Shan,Qi, Bing,Shi, Pengfei,Wang, Qi,Zhu, Jin
-
supporting information
(2020/03/10)
-
- The Synthesis of Primary Amines through Reductive Amination Employing an Iron Catalyst
-
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.
- B?umler, Christoph,Bauer, Christof,Kempe, Rhett
-
p. 3110 - 3114
(2020/06/01)
-
- Facile synthesis of controllable graphene-co-shelled reusable Ni/NiO nanoparticles and their application in the synthesis of amines under mild conditions
-
The primary objective of many researchers in chemical synthesis is the development of recyclable and easily accessible catalysts. These catalysts should preferably be made from Earth-abundant metals and have the ability to be utilised in the synthesis of pharmaceutically important compounds. Amines are classified as privileged compounds, and are used extensively in the fine and bulk chemical industries, as well as in pharmaceutical and materials research. In many laboratories and in industry, transition metal catalysed reductive amination of carbonyl compounds is performed using predominantly ammonia and H2. However, these reactions usually require precious metal-based catalysts or RANEY nickel, and require harsh reaction conditions and yield low selectivity for the desired products. Herein, we describe a simple and environmentally friendly method for the preparation of thin graphene spheres that encapsulate uniform Ni/NiO nanoalloy catalysts (Ni/NiO?C) using nickel citrate as the precursor. The resulting catalysts are stable and reusable and were successfully used for the synthesis of primary, secondary, tertiary, and N-methylamines (more than 62 examples). The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, and H2 under very mild industrially viable and scalable conditions (80 °C and 1 MPa H2 pressure, 4 h), offering cost-effective access to numerous functionalized, structurally diverse linear and branched benzylic, heterocyclic, and aliphatic amines including drugs and steroid derivatives. We have also demonstrated the scale-up of the heterogeneous amination protocol to gram-scale synthesis. Furthermore, the catalyst can be immobilized on a magnetic stirring bar and be conveniently recycled up to five times without any significant loss of catalytic activity and selectivity for the product.
- Cui, Zhibing,Liu, Jianguo,Liu, Qiying,Ma, Longlong,Singh, Thishana,Wang, Chenguang,Wang, Nan,Zhu, Yuting
-
supporting information
p. 7387 - 7397
(2020/11/19)
-
- Reductive amination of ketonic compounds catalyzed by Cp*Ir(III) complexes bearing a picolinamidato ligand
-
Cp*Ir complexes bearing a 2-picolinamide moiety serve as effective catalysts for the direct reductive amination of ketonic compounds to give primary amines under transfer hydrogenation conditions using ammonium formate as both the nitrogen and hydrogen source. The clean and operationally simple transformation proceeds with a substrate to catalyst molar ratio (S/C) of up to 20,000 at relatively low temperature and exhibits excellent chemoselectivity toward primary amines.
- Tanaka, Kouichi,Miki, Takashi,Murata, Kunihiko,Yamaguchi, Ayumi,Kayaki, Yoshihito,Kuwata, Shigeki,Ikariya, Takao,Watanabe, Masahito
-
p. 10962 - 10977
(2019/09/03)
-
- Method for synthesizing chiral amine compound
-
The present invention provides a method for synthesizing a chiral amine compound. The method comprises the following steps: (1) reacting a compound of formula I with t-butylsulfonamide in the presenceof a catalyst to obtain a compound having a structure represented by formula II; 2) reacting the compound of the formula II in a hydrogen atmosphere in the presence of an iridium catalyst and a ligand to obtain a compound of formula III; and (3) carrying out a t-butylsulfonyl group removal reaction on the compound of the formula III to obtain the chiral amine compound. The method constructs the structure of sulfonamide by a keto carbonylgroup, and synthesizes the chiral amine compound with the aralkylamine structure by an asymmetric catalytic hydrogenation reaction of the sulfonamide structure, the ee value is generally 80% or above, the highest ee value is 99% or above, the yield of each step reaction can reach 90% or above, and the total yield is high.
- -
-
Paragraph 0064; 0071-0073; 0123-0125
(2019/10/01)
-
- METHOD FOR THE HOMOGENEOUS CATALYTIC REDUCTIVE AMINATION OF CARBONYL COMPOUNDS
-
The present invention relates to a method for the reductive amination of a carbonyl compound, comprising one or more carbonyl groups amenable to reductive amination, forming the corresponding primary amine, characterized in that the reaction is carried out in the presence of a homogeneously dissolved catalyst complex K, comprising at least one metal atom from Group 8, 9 or 10 of the periodic table, bearing a bidentate phosphane ligand, a carbonyl ligand, a neutral ligand and a hydride ligand, and also an acid as co-catalyst.
- -
-
Paragraph 0212; 0219-0221
(2018/07/29)
-
- Arynes and Cyclic Alkynes as Synthetic Building Blocks for Stereodefined Quaternary Centers
-
We report a facile method to synthesize stereodefined quaternary centers from reactions of arynes and related strained intermediates using β-ketoester-derived substrates. The conversion of β-ketoesters to chiral enamines is followed by reaction with in situ generated strained arynes or cyclic alkynes. Hydrolytic workup provides the arylated or alkenylated products in enantiomeric excesses as high as 96%. We also describe the one-pot conversion of a β-ketoester substrate to the corresponding enantioenriched α-arylated product. Computations show how chirality is transferred from the N-bound chiral auxiliary to the final products. These are the first theoretical studies of aryne trapping by chiral nucleophiles to set new stereocenters. Our approach provides a solution to the challenging problem of stereoselective β-ketoester arylation/alkenylation, with formation of a quaternary center.
- Picazo, Elias,Anthony, Sarah M.,Giroud, Maude,Simon, Adam,Miller, Margeaux A.,Houk,Garg, Neil K.
-
supporting information
p. 7605 - 7610
(2018/05/15)
-
- Asymmetric Synthesis of Chiral Primary Amines by Ruthenium-Catalyzed Direct Reductive Amination of Alkyl Aryl Ketones with Ammonium Salts and Molecular H2
-
A ruthenium/C3-TunePhos catalytic system has been identified for highly efficient direct reductive amination of simple ketones. The strategy makes use of ammonium acetate as the amine source and H2 as the reductant and is a user-friendly and operatively simple access to industrially relevant primary amines. Excellent enantiocontrol (>90% ee for most cases) was achieved with a wide range of alkyl aryl ketones. The practicability of this methodology has been highlighted by scalable synthesis of key intermediates of three drug molecules. Moreover, an improved synthetic route to the optimal diphosphine ligand C3-TunePhos is also presented.
- Tan, Xuefeng,Gao, Shuang,Zeng, Weijun,Xin, Shan,Yin, Qin,Zhang, Xumu
-
supporting information
p. 2024 - 2027
(2018/02/19)
-
- Synthesis and pKa determination of new enantiopure dimethyl-substituted acridino-crown ethers containing a carboxyl group: Useful candidates for enantiomeric recognition studies
-
New enantiopure dimethyl-substituted acridino-18-crown-6 and acridino-21-crown-7 ethers containing a carboxyl group at position 9 of the acridine ring [(S,S)-8, (S,S)-9, (R,R)-10] were synthesized. The pKa values of the new crown ethers [(S,S)-8, (S,S)-9, (R,R)-10] and of an earlier reported macrocycle [(R,R)-2] were determined by UV-pH titrations. Crown ether (S,S)-8 was attached to silica gel by covalent bonds and the enantiomeric separation ability of the newly prepared chiral stationary phase [(S,S)-CSP-12] was studied by high-performance liquid chromatography (HPLC). Homochiral preference was observed and the best separation was achieved for the enantiomers of 1-NEA. Ligands (S,S)-9 and (R,R)-10 are precursors of enantioselective sensor and selector molecules for the enantiomers of protonated primary amines, amino acids, and their derivatives.
- Németh, Tamás,Dargó, Gerg?,Petró, József Levente,Petrik, Zsófia,Lévai, Sándor,Krámos, Balázs,Béni, Zoltán,Nagy, József,Balogh, Gy?rgy Tibor,Huszthy, Péter,Tóth, Tünde
-
p. 522 - 535
(2017/08/26)
-
- Direct Synthesis of Primary Amines via Ruthenium-Catalysed Amination of Ketones with Ammonia and Hydrogen
-
A highly selective reductive amination of ketones to primary amines with ammonia and hydrogen using a simple ruthenium catalyst has been developed. The protocol described constitutes an efficient and direct atom-economical approach en route to α-methylbenzylamine derivatives in good to high yields. The presence of catalytic amounts of aluminum triflate turned out to be crucial for achieving high conversion towards primary amines.
- Gallardo-Donaire, Joan,Ernst, Martin,Trapp, Oliver,Schaub, Thomas
-
supporting information
p. 358 - 363
(2016/04/26)
-
- CATALYST COMPOUNDS
-
The present invention relates to an iridium-based catalyst compound for hydrogenating reducible moieties, especially imines and iminiums, the catalyst compounds being defined by the formula: (Formula (I)) where ring B is a conjugated ring system with one or more substituents. The catalysts of the invention are particularly effective in reductive amination procedures which involve the in situ generation of the imine or iminium under reductive hydrogenative conditions.
- -
-
Paragraph 0297; 0303
(2015/03/16)
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- PROCESS FOR THE PREPARATION OF CHIRAL AMINES FROM PROCHIRAL KETONES
-
There is provided a method for the preparation of an enantiomerically enriched amine from a prochiral ketone.
- -
-
Page/Page column 5; 6
(2015/12/11)
-
- PROCESS FOR THE PREPARATION OF CHIRAL AMINES BY ASYMMETRIC HYDROGENATION OF PROCHIRAL OXIMES
-
There is provided a method for the preparation of an enantiomerically enriched amine by asymmetric hydrogenation of a prochiral oxime.
- -
-
Page/Page column 5-7
(2015/12/08)
-
- PRODUCTION METHOD FOR COMPOUND COMPRISING AMINO GROUP AND/OR HYDROXYL GROUP
-
Disclosed is a method for producing a compound having an amino group and/or a hydroxyl group from a substrate compound having an atomic group containing CO or CS by eliminating said atomic group. The substrate compound having an atomic group containing CO or CS (for example, an amide, a carbamate, or the like) is allowed to react with a compound expressed by formula (I) below, at a temperature of 120°C or lower, preferably in the presence of an ammonium salt, to eliminate said atomic group containing CO or CS. In formula (I) A may not be present, and in a case where A is present, A represents an alkyl group having 1 to 6 carbon atoms. ????????H2N-A-NH2?????(I)
- -
-
Paragraph 0071
(2015/01/18)
-
- APPLICATIONS OF N6-SUBSTITUTED ADENOSINE DERIVATIVE AND N6-SUBSTITUTED ADENINE DERIVATIVE TO CALMING, HYPNOSES, CONVULSION RESISTANCE, EPILEPTIC RESISTANCE, PARKINSON DISEASE RESISTANCE, AND DEMENTIA PREVENTION AND TREATMENT
-
PROBLEM TO BE SOLVED: To prepare analgesics, hypnotic agents, anticonvulsant agents, antiepileptics, antiparkinson drugs, dementia prophylactics, and health care food. SOLUTION: The present invention relates to an N6-substituted adenosine derivative and an N6-substituted adenine derivative selected from the group consisting of specific compounds. The present invention also relates to a pharmaceutical composition at least comprising a therapeutically effective amount of the compounds and a pharmaceutically acceptable carrier. The invention further relates to the compounds used in preparation of analgesics, hypnotic agents, anticonvulsant agents, antiepileptics, antiparkinson drugs, dementia prophylactics, and health care food. COPYRIGHT: (C)2016,JPO&INPIT
- -
-
Paragraph 0183
(2018/10/27)
-
- CATALYST COMPOUNDS
-
The present invention relates to an iridium-based catalyst compound for hydrogenating reducible moieties, especially imines and iminiums, the catalyst compounds being defined by the formulas: where ring B is either itself polycyclic, or ring B together with R is polycyclic. The catalysts of the invention are particularly effective in reductive amination procedures 10 which involve the in situ generation of the imine or iminium under reductive hydrogenative conditions.
- -
-
Paragraph 0314; 0321
(2015/03/28)
-
- Primary amines by transfer hydrogenative reductive amination of ketones by using cyclometalated IrIII catalysts
-
Cyclometalated iridium complexes are found to be versatile catalysts for the direct reductive amination (DRA) of carbonyls to give primary amines under transfer-hydrogenation conditions with ammonium formate as both the nitrogen and hydrogen source. These complexes are easy to synthesise and their ligands can be easily tuned. The activity and chemoselectivity of the catalyst towards primary amines is excellent, with a substrate to catalyst ratio (S/C) of 1000 being feasible. Both aromatic and aliphatic primary amines were obtained in high yields. Moreover, a first example of homogeneously catalysed transfer-hydrogenative DRA has been realised for β-keto ethers, leading to the corresponding β-amino ethers. In addition, non-natural α-amino acids could also be obtained in excellent yields with this method. Reduce the work! A broad range of ketones have been successfully aminated to afford primary amines under transfer-hydrogenation conditions by using ammonium formate as the amine source and 0.1 mol % of a cyclometalated IrIII catalyst (see scheme). Copyright
- Talwar, Dinesh,Salguero, Noemi Poyatos,Robertson, Craig M.,Xiao, Jianliang
-
p. 245 - 252
(2014/01/17)
-
- Microwave-Enhanced Asymmetric Transfer Hydrogenation of N-(tert-Butylsulfinyl)imines
-
Microwave irradiation has considerably enhanced the efficiency of the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)imines in isopropyl alcohol catalyzed by a ruthenium complex bearing the achiral ligand 2-amino-2-methylpropan-1-ol. In addition to shortening reaction times for the transfer hydrogenation processes to only 30 min, the amounts of ruthenium catalyst and isopropyl alcohol can be considerably reduced in comparison with our previous procedure assisted by conventional heating, which diminishes the environmental impact of this new protocol. This methodology can be applied to aromatic, heteroaromatic and aliphatic N-(tert-butylsulfinyl)ketimines, leading, after desulfinylation, to the expected primary amines in excellent yields and with enantiomeric excesses of up to 96 %. Microwave irradiation promotes the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)imines in 2-propanol catalysed by a ruthenium complex bearing an achiral β-amino alcohol as ligand. After desulfinylation, α-branched primary amines containing aromatic, heteroaromatic and aliphatic substituents are obtained in excellent yields and with enantiomeric excesses of up to 96 %.
- Pablo, Oscar,Guijarro, David,Yus, Miguel
-
p. 7034 - 7038
(2016/02/19)
-
- From racemic alcohols to enantiopure amines: Ru-catalyzed diastereoselective amination
-
A commercially available ruthenium(II) PNP-type pincer catalyst (Ru-Macho) promotes the formation of α-chiral tert-butanesulfinylamines from racemic secondary alcohols and Ellmans chiral tert-butanesulfinamide via a hydrogen borrowing strategy. The formation of α-chiral tert-butanesulfinylamines occurs in yields ranging from 31% to 89% with most examples giving >95:5 dr.
- Oldenhuis, Nathan J.,Dong, Vy M.,Guan, Zhibin
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p. 12548 - 12551
(2014/12/10)
-
- Kinetic resolution of primary amines via enantioselective N-acylation with acyl chlorides in the presence of supramolecular cyclodextrin nanocapsules
-
The non-enzymatic kinetic resolution of primary amines via enantioselective N-acylation with acyl chlorides was accomplished for the first time by using the selective sequestration of one enantiomer within a supramolecular cyclodextrin (CD) nanocapsule in nonpolar solvents. In addition, the first example of a crystalline structure for an inclusion complex between an acyl chloride and a CD derivative is reported.
- Asahara, Haruyasu,Kida, Toshiyuki,Iwamoto, Takuya,Hinoue, Tomoaki,Akashi, Mitsuru
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p. 197 - 203
(2014/01/06)
-
- Liquid chromatographic resolution of fendiline and its analogues on a chiral stationary phase based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid
-
Fendiline, an effective anti-anginal drug for the treatment of coronary heart diseases, and its sixteen analogues were resolved on a CSP based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid. Fendiline was resolved quite well with the separation factor (α) of 1.25 and resolution (RS ) of 1.55 when a mobile phase consisting of methanol-acetonitrile-trifluoroacetic acid-triethylamine at a ratio of 80/20/0.1/0.5 (v/v/v/v) was used. The comparison of the chromatographic behaviors for the resolution of fendiline and its analogues indicated that the 3,3-diphenylpropyl group bonded to the secondary amino group of fendiline is important in the chiral recognition and the difference in the steric bulkiness between the phenyl group and the methyl group at the chiral center of fendiline is also important in the chiral recognition.
- Lee, Ga Ram,Hyun, Myung Ho
-
p. 21386 - 21397
(2015/02/19)
-
- CATALYST COMPOUNDS
-
The present invention relates to an iridium-based catalyst compound for hydrogenating reducible moieties, especially imines and iminiums, the catalyst compounds being defined by the formula: (Formula (I)) where ring B is a conjugated ring system with one or more substituents. The catalysts of the invention are particularly effective in reductive amination procedures which involve the in situ generation of the imine or iminium under reductive hydrogenative conditions.
- -
-
Paragraph 00141; 00145; 00147
(2013/11/05)
-
- Nickel nanoparticles as racemization catalysts for primary amines
-
By combining bases that are known to racemize benzylic amines with a nickel(II) salt, active nickel nanoparticles were obtained that can be used as catalysts in the racemization of both aliphatic and benzylic primary amines. The nanoparticles are stable in the ionic liquid tetrabutylammonium bromide and can complete most racemizations within a few hours with excellent selectivity. The problem of the incompatibility of the strongly reducing racemization catalyst and the enzymatic amine resolution catalyst was overcome by using a two-pot system with a biphasic racemization step. Consecutive contact of a nonane layer that contained the amine with the acylating enzyme and with the racemizing Ni nanoparticles in the ionic liquid allowed the 50 % amide yield limit of a kinetic resolution to be successfully surpassed. Copyright
- Geukens, Inge,Plessers, Eva,Seo, Jin Won,De Vos, Dirk E.
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p. 2623 - 2628
(2013/07/11)
-
- Investigation of one-enzyme systems in the ω-transaminase-catalyzed synthesis of chiral amines
-
ω-Transaminase (TA) catalyzed asymmetric syntheses of amines were carried out in the one enzyme systems with wild-type enzymes (S)-TA from Pseudomonas aeruginosa, (S)-TA from Paracoccus denitrificans and (R)-TA from Aspergillus terreus. The scope of amine donors and aromatic carbonyl substrates was thoroughly explored. Among the range of potential amino donors, 2-propylamine, 2-butylamine and 1-phenylethylamine were found as promising candidates, which gave superior conversions in the amination reactions compared to other donors. Various prochiral aromatic ketones were accepted as substrates by the investigated enzymes. In most cases, good to excellent conversions (up to 98%) to the amine products with excellent e.e.-values (>99.9% for (S) or (R)) were obtained by the action of a single enzyme and an appropriate amino donor. (S)-TA from Paracoccus denitrificans was found to accept bulky ketones, e.g. 1-indanone, α- and β-tetralone or 2-acetonaphthone, in the asymmetric amination. In some cases the enantiomeric excesses in the amination reactions were dependent on the amino donor. More-over, the influence of the pH, temperature and cosolvents on the outcome of reactions was additionally investigated.
- Fesko, Kateryna,Steiner, Kerstin,Breinbauer, Rolf,Schwab, Helmut,Schuermann, Martin,Strohmeier, Gernot A.
-
p. 103 - 110
(2013/10/22)
-
- CATALYST COMPOUNDS
-
The present invention relates to an iridium-based catalyst compound for hydrogenating reducible moieties, especially imines and iminiums, the catalyst compounds being defined by the formulas: where ring B is either itself polycyclic, or ring B together with R is polycyclic. The catalysts of the invention are particularly effective in reductive amination procedures 10 which involve the in situ generation of the imine or iminium under reductive hydrogenative conditions.
- -
-
Paragraph 00163; 00170
(2013/11/05)
-
- Organocatalytic asymmetric biomimetic transamination of aromatic ketone to optically active amine
-
An asymmetric biomimetic transamination of aromatic ketones to optically active amines with o-HOPhCH2NH2 as amine source catalyzed by hydroquinine-derived chiral base is described. Up to 85% ee was obtained.
- Xie, Ying,Pan, Hongjie,Xiao, Xiao,Li, Songlei,Shi, Yian
-
supporting information
p. 8960 - 8962,3
(2012/12/12)
-
- Organocatalytic asymmetric biomimetic transamination of aromatic ketone to optically active amine
-
An asymmetric biomimetic transamination of aromatic ketones to optically active amines with o-HOPhCH2NH2 as amine source catalyzed by hydroquinine-derived chiral base is described. Up to 85% ee was obtained.
- Xie, Ying,Pan, Hongjie,Xiao, Xiao,Li, Songlei,Shi, Yian
-
supporting information
p. 8960 - 8962
(2013/01/15)
-
- Thermodynamics of phenylacetamides synthesis: Linear free energy relationship with the pK of amine
-
The effective equilibrium constants K′C expressed through the total concentrations of the reagents for the synthesis of N-phenylacetyl-derivatives in aqueous medium from phenylacetic acid and various primary amino compounds have been determined with penicillin acylase as a catalyst. Broad specificity of penicillin acylase (EC 3.5.1.11) to amino components made possible to investigate the acylation of primary amines with different structures and physicochemical properties. Analysis of different components of the effective standard Gibbs energy change ΔGC o′ has revealed favorable thermodynamics for the synthesis of phenylacetamides from unionized substrates forms, however the ionization of reactants carboxy and amino groups in aqueous solutions pushes the equilibrium position to the hydrolysis especially in case of highly basic amines. A linear correlation between the standard Gibbs energy change for amide bond formation from the unionized reagents species and the basicity of amino group was observed: ΔGTo=-3.56pKamine+7.71(kJ/mol). The established linear free energy relationship (LFER) allows to predict the thermodynamic parameters for direct condensation of phenylacetic acid with any amine of known pK. Condensation of phenylacetic acid and amines with pK value within 1.5-8.5 was shown to be thermodynamically favorable in homogeneous aqueous solution. .
- Guranda, Dorel T.,Ushakov, Gennadij A.,Yolkin, Petr G.,Svedas, Vytas K.
-
experimental part
p. 48 - 53
(2012/05/19)
-
- Reductive amination of ketones: Novel one-step transfer hydrogenations in batch and continuous-flow mode
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Various ketones were efficiently transformed into the corresponding amines using ammonium formate in the presence of Zn dust or 10% Pd/C. The low-cost Zn dust method proved to be effective in amine formation from carbonyl groups at the benzylic side-chain position of aromatic systems, whereas 10% Pd/C was an efficient catalyst in the reductive aminations of carbonyl groups non-conjugated with any π-system. The 10% Pd/C-catalyzed reductions were performed more effectively in a continuous-flow X-Cube reactor than in the batch system.
- Falus, Péter,Boros, Zoltán,Hornyánszky, Gábor,Nagy, József,Darvas, Ferenc,ürge, László,Poppe, László
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supporting information; experimental part
p. 1310 - 1312
(2011/03/22)
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- Asymmetric synthesis of chiral primary amines by transfer hydrogenation of N -(tert -Butanesulfinyl)ketimines
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(Figure presented) The diastereoselective reduction of (R)-N-(tert- butanesulfinyl)ketimines by a ruthenium-catalyzed asymmetric transfer hydrogenation process in isopropyl alcohol, followed by desulfinylation of the nitrogen atom, is an excellent method to prepare highly enantiomerically enriched α-branched primary amines (up to >99% ee) in short reaction times (1-4 h). (1S,2R)-1-Amino-2-indanol has been shown to be a very efficient ligand to perform this transformation. Ketimines bearing either an aryl or a heteroaryl group and an alkyl group as substituents of the iminic carbon atom are very good substrates for this process. The reduction of a dialkyl ketimine could also be achieved, affording the expected amine with moderate optical purity (69% ee). Some amines which are precursors of very interesting biologically and pharmacologically active compounds have been prepared in excellent yields and enantiomeric excesses.
- Guijarro, David,Pablo, Oscar,Yus, Miguel
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supporting information; experimental part
p. 5265 - 5270
(2010/10/21)
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- COMPOSITIONS AND METHODS FOR CYCLOFRUCTANS AS SEPARATION AGENTS
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The present invention relates to derivatized cyclofructan compounds, compositions comprising derivatized cyclofructan compounds, and methods of using compositions comprising derivatized cyclofructan compounds for chromatographic separations of chemical species, including enantiomers. Said compositions may comprise a solid support and/or polymers comprising derivatized cyclofructan compounds.
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Page/Page column 46-47
(2010/12/31)
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- A versatile catalyst for reductive animation by transfer hydrogenation
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An iridium catalyst enables the reductive amination of carbonyl groups with unprecedented substrate scope, selectivity, and activity using formic acid as the hydrogen source (see scheme) The catalyst system provides significant improvement over commonly used boron hydrides.
- Wang, Chao,Pettman, Alan,Basca, John,Xiao, Jianliang
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supporting information; experimental part
p. 7548 - 7552
(2010/12/19)
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- Rapid, one-pot synthesis of α,α-disubstituted primary amines by the addition of Grignard reagents to nitriles under microwave heating conditions
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A series of α,α-disubstituted amines have been prepared in a simple and efficient one-pot procedure by the addition of Grignard reagents to a series of aliphatic, aromatic, and heteroaromatic nitriles. Key to this reported procedure is the unprecedented addition of the Grignard reagent to the nitrile under heating by microwave irradiation which both significantly improves reaction yields and reduces reaction times. In general, the Grignard addition reaction is complete within 5-10 min at 100 °C followed by rapid reduction with sodium borohydride to give the target amines.
- Gregg, Brian T.,Golden, Kathryn C.,Quinn, John F.,Wang, Hong-Jun,Zhang, Wei,Wang, Ruifang,Wekesa, Francis,Tymoshenko, Dmytro O.
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experimental part
p. 3978 - 3981
(2009/10/04)
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- Iridium/monodentate phosphoramidite catalyzed asymmetric hydrogenation of N-aryl imines
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(Chemical Equation Presented) Asymmetric hydrogenation of N-aryl acetophenone imines using iridium/PipPhos leads to very high enantioselectivities up to >99percent depending on the presence of electron-donating substituents in the 2-, 3-, and 5-position of the aryl ring. If the substituent is 2-methoxy, the resultant secondary amines are easily oxidatively deprotected using trichloroisocyanuric acid to give the primary amines ingood yield with full retention of enantioselectivity.
- Mrsic, Natasa,Minnaard, Adriaan J.,Feringa, Ben L.,Vries, Johannes G. de
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supporting information; experimental part
p. 8358 - 8359
(2009/10/23)
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- Heterogeneous raney nickel and cobalt catalysts for racemization and dynamic kinetic resolution of amines
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Raney metals were studied as heterogeneous catalysts for racemization and dynamic kinetic resolution (DKR) of chiral amines, as an alternative to metals like palladium or ruthenium. Both Raney nickel and cobalt were able to selectively racemize various chiral amines with high selectivity. In the racemization of benzylic primary amines, the minor formation of side products, e.g., secondary amines, can be suppressed by varying the hydrogen pressure. In the racemization of aliphatic amines over Raney catalysts, the selectivity is very high, with the enantiomeric amine as the sole product. DKR of racemic aliphatic amines can be performed with immobilized Candida antarctica lipase B and Raney nickel in one pot; for 2-hexylamine, a yield of 95% of the acetylated amide was achieved, with 97% ee. Attention is devoted to the compatibility of the enzyme and the metal catalyst during the DKR. For benzylic primary amines, a two-pot process is proposed in which the liquid is alternatingly shuttled between two vessels containing the solid racemization catalyst and the biocatalyst. After 4 such cycles, the amide of (R)-1-phenylethylamine was obtained with 94% yield and more than 90% ee.
- Parvulescu, Andrei N.,Jacobs, Pierre A.,De Vos, Dirk E.
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scheme or table
p. 113 - 121
(2009/04/16)
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- AMIDE COMPOUND AND METHOD OF CONTROLLING PLANT DISEASE WITH THE SAME
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A amid compound of the formula (1): wherein, in the formula, R51 represents a halogen atom, a C1-C6 alkyl group and the like; R52 represents a hydrogen atom, a halogen atom, a C1-C6 alkyl group and the like; R53 represents a halogen atom and the like; R56 represents a halogen atom and the like; R57 represents a hydrogen atom and the like; R58 and R59 independently represent a hydrogen atom, a C1-C3 alkyl group and the like; R60 represents a C1-C4 alkyl group, a C1-C4 haloalkyl group, a C3-C4 alkenyl group, or a C3-C6 alkynyl group; R61 represents a C1-C4 alkyl group, a C1-C4 haloalkyl group, a C3-C4 alkenyl group or a C3-C6 alkynyl group or a C2-C4 cyanoalkyl group; R62, R63 and R64 represent a hydrogen atom, a halogen atom and the like; X represents a oxygen atom or a sulfur atom; has an excellent activity against plant diseases.
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Page/Page column 107
(2010/02/14)
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- Synthesis of enantiopure 6-methoxy-2-naphthylglycolic acid and its application as a resolving agent
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6-Methoxy-2-naphthylglycolic acid (6-MNGA) was designed as a novel acidic resolving agent, on the model of 2-naphthylglycolic acid (2-NGA). Enantiopure 6-MNGA was easily obtained from commercially available 2-bromo-6- methoxynaphthalene through four steps and was found to show a better chiral recognition ability for racemic 1-arylethylamines than the prototype 2-NGA did. The X-ray crystallographic analyses of less-soluble diastereomeric salts revealed that the introduction of a methoxy group at the 6-position of the 2-NGA skeleton made CH/π interaction(s) effective between 6-MNGA molecules and also between the 6-MNGA molecule and the target amine molecule. The methoxy group was also found to contribute to the realization of effective van der Waals interaction. These interactions played important roles for the stabilization of the less-soluble diastereomeric salts to improve the chiral recognition ability of 6-MNGA, compared to that of 2-NGA.
- Shimada, Takayoshi,Kobayashi, Yuka,Saigo, Kazuhiko
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p. 3807 - 3813
(2007/10/03)
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- Highly Enantioselective Hydrogen-Transfer Reductive Amination: Catalytic Asymmetric Synthesis of Primary Amines
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Ammonium formate is the hydrogen source in the catalytic asymmetric reductive amination of ketones presented here (Leuckart-Wallach-type reaction). The reaction proceeds smoothly in methanol in the presence of Ir, Rh, and Ru catalysts. Primary amines were obtained as products in good yields with high enantioselectivities after hydrolytic workup when [((R)-tol-binap) RuCl 2] was used as the catalyst (see scheme). R1, R 2=alkyl, aryl.
- Kadyrov, Renat,Riermeier, Thomas H.
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p. 5472 - 5474
(2007/10/03)
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- Synthesis of enantiomerically pure amino-substituted fused bicyclic rings
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This invention describes various processes for synthesis and resolution of racemic amino-substituted fused bicyclic ring systems. One process utilizes selective hydrogenation of an amino-substituted fused bicyclic aromatic ring system. An alternative process prepares the racemic amino-substituted fused bicyclic ring system via nitrosation. In addition, the present invention describes the enzymatic resolution of a racemic mixture to produce the (R)- and (S)-forms of amino-substituted fused bicyclic rings as well as a racemization process to recycle the unpreferred enantioner. Further provided by this invention is an asymmetric synthesis of the (R)- or (S)-enantiomer of primary amino-substituted fused bicyclic ring systems.
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- Resolution of 1-arylethylamines with 5-(1,2-O-isopropylidene-3,6-anhydro- α-D-glucofuranosyl) hydrogen phthalate
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The potential of the hydrogen phthalate of 1,2-O-isopropylidene-3,6- anhydro-α-D-glucofuranose 1 obtainable by the reaction of phthalic anhydride with 1,2-O-isopropylidene-3,6-anhydro-α-D-glucofuranose 8 as a new resolving agent is shown. The salts between 1 and (RS)-1-arylethylamines 2-6 and (RS)-1-arylpropylamine 7 selectively crystallize 1·(R)-salts allowing the recovery of the corresponding (R)-amines 2-7. The more soluble 1·(S)-salts were analogously processed to obtain (S)-amines, respectively. In all of the cases (R)- and (S)-amines 2-7 were obtained in high chemical yield and enantiomeric excess >98%. Resolving agent 1 has been recovered in a quantitative yield and high purity.
- Mereyala, Hari Babu,Pola, Pallavi
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p. 2683 - 2685
(2007/10/03)
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- An efficient and mild ruthenium-catalyzed racemization of amines: Application to the synthesis of enantiomerically pure amines
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An efficient and mild Ru-catalyzed racemization of amines under transfer hydrogenation conditions is reported. A significant advantage of this new procedure is that the ruthenium hydrogen transfer catalysts allow high functional group tolerance. Interestingly, both primary and secondary amines were efficiently racemized under these conditions. We also report on the combination of this new amine racemization with an enzymatic kinetic resolution of primary amines.
- Pàmies, Oscar,éll, Alida H.,Samec, Joseph S.M.,Hermanns, Nina,B?ckvall, Jan-E.
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p. 4699 - 4702
(2007/10/03)
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- Acetamide and substituted acetamide-containing thiourea inhibitors of herpes viruses
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Compounds of the formula: are useful in the treatment of diseases associated with herpes viruses including human cytomegalovirus, herpes simplex viruses, Epstein-Barr virus, varicella-zoster virus, human herpesviruses-6 and -7, and Kaposi herpesvirus.
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