15996-84-6Relevant articles and documents
Rh(III)-catalyzed synthesis of isoquinolines using the N-Cl bond of N-chloroimines as an internal oxidant
Chu, Benfa,Fang, Lili,Guo, Shan,Qi, Bing,Shi, Pengfei,Wang, Qi,Zhu, Jin
supporting information, (2020/03/10)
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.
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.
Rh(III)-Catalyzed Coupling of N-Chloroimines with α-Diazo-α-phosphonoacetates for the Synthesis of 2 H-Isoindoles
Qi, Bing,Li, Lei,Wang, Qi,Zhang, Wenjing,Fang, Lili,Zhu, Jin
supporting information, p. 6860 - 6863 (2019/09/12)
We report herein the first use of N-chloroimines as effective synthons for directed C-H functionalization. Rh(III)-catalyzed coupling of N-chloroimines with α-diazo-α-phosphonoacetates allows for efficient dechlorinative/dephosphonative access to 2H-isoindoles. Further deesterification under Ni(II) catalysis enables the complete elimination of reactivity-assisting groups and full exposure of reactivity of C3 and N2 ring atoms for attaching structurally distinct appendages.
Substituent effects on chiral resolutions of derivatized 1-phenylalkylamines by heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-β-cyclodextrin GC stationary phase
Issaraseriruk, Natthapol,Sritana-anant, Yongsak,Shitangkoon, Aroonsiri
supporting information, p. 900 - 906 (2018/05/08)
Chiral resolutions of trifluoroacetyl-derivatized 1-phenylalkylamines with different type and position of substituent were investigated by capillary gas chromatography by using heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-β-cyclodextrin diluted in OV-1701 as a chiral stationary phase. The influence of column temperature on retention and enantioselectivity was examined. All enantiomers of meta-substituted analytes as well as fluoro-substituted analytes could be resolved. Temperature had a favorable influence on enantioselectivity for small amines with substituents at the ortho-position. The type of substituent at the stereogenic center of amines also had a crucial effect as the ethyl group led to poor enantioseparation. Among all analytes studied, trifluoroacetyl-derivatized 1-(2′-fluorophenyl)ethylamine exhibited baseline resolution with the shortest analysis time.
N-Alkylation of Aqueous Ammonia with Alcohols Leading to Primary Amines Catalyzed by Water-Soluble N-Heterocyclic Carbene Complexes of Iridium
Fujita, Ken-Ichi,Furukawa, Shohichi,Morishima, Namino,Shimizu, Mineyuki,Yamaguchi, Ryohei
, p. 1993 - 1997 (2018/03/13)
A new catalytic system for the N-monoalkylation of aqueous ammonia with a variety of alcohols was developed. Water-soluble dicationic complexes of iridium bearing N-heterocyclic carbene and diammine ligands exhibited high catalytic activity for this type of reaction on the basis of hydrogen-transfer processes without generating harmful or wasteful byproducts. Various primary amines were efficiently synthesized by using safe, inexpensive, and easily handled aqueous ammonia as a nitrogen source. For example, the reaction of 1-(4-methylphenyl)ethanol with aqueous ammonia in the presence of a water-soluble N-heterocyclic carbene complex of iridium at 150 °C for 40 h gave 1-(4-methylphenyl)ethylamine in 83 % yield.
METHOD FOR THE HOMOGENEOUS CATALYTIC REDUCTIVE AMINATION OF CARBONYL COMPOUNDS
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Paragraph 0212; 0219-0221, (2018/07/29)
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.
Versatile Dynamic Covalent Assemblies for Probing π-Stacking and Chirality Induction from Homotopic Faces
Ye, Hebo,Hai, Yu,Ren, Yulong,You, Lei
supporting information, p. 3804 - 3809 (2017/03/27)
Herein we report for the first time the use of dynamic covalent reactions (DCRs) for building a π-stacking model system and further quantifying its substituent effects (SEs), which remain a topic of debate despite the rich history of stacking. A general DCR between 10-methylacridinium ion and primary amines was discovered, in which π-stacking played a stabilizing role. Facile quantification of SEs with in situ competing π-stacking systems was next achieved in the form of amine exchange exhibiting structural diversity by simply varying components. The linear correlation with σm in Hammett plots indicates the dominance of purely electrostatic SEs, and the additivity of SEs is in line with the direct interaction model. With α-chiral amines π-stacking within the adduct enabled chirality transfer from homotopic faces. The strategy of dynamic covalent assembly should be appealing to future research of probing weak interactions and manipulating chirality.
Asymmetric Biocatalytic Synthesis of Fluorinated Pyridines through Transesterification or Transamination: Computational Insights into the Reactivity of Transaminases
López-Iglesias, María,González-Martínez, Daniel,Rodríguez-Mata, María,Gotor, Vicente,Busto, Eduardo,Kroutil, Wolfgang,Gotor-Fernández, Vicente
supporting information, p. 279 - 291 (2017/02/05)
The synthesis of a family of pyridines bearing a fluorinated substituent on the aromatic ring has been carried out through two independent and highly stereoselective chemoenzymatic strategies. Short chemical synthetic routes toward fluorinated racemic amines and prochiral ketones have been developed, which served as substrates to explore the suitability of lipases and transaminases in asymmetric biotransformations. The lipase-catalyzed kinetic resolution via acylation of racemic amines proceeded smoothly giving conversions close to 50% and excellent enantioselectivities. Alternatively, the biotransamination of the corresponding prochiral ketones was investigated giving access to both optically pure amine enantiomers using transaminases with complementary selectivity. High to quantitative conversion values were achieved, which allowed the isolation of the amines in moderate to high yields (40–88%). A deeper understanding of the latter process was enabled by performing theoretical calculations on thermodynamic and mechanistic aspects. Calculations showed that the biotransamination reactions are highly favoured by the presence of fluorine atoms and the pyridine ring. (Figure presented.).
Stereoselective amination of racemic sec-alcohols through sequential application of laccases and transaminases
Martínez-Montero, Lía,Gotor, Vicente,Gotor-Fernández, Vicente,Lavandera, Iván
supporting information, p. 474 - 480 (2017/06/23)
A one-pot/two-step bienzymatic asymmetric amination of secondary alcohols is disclosed. The approach is based on a sequential strategy involving the use of a laccase/TEMPO catalytic system for the oxidation of alcohols into ketone intermediates, and their following transformation into optically enriched amines by using transaminases. Individual optimizations of the oxidation and biotransamination reactions have been carried out, studying later their applicability in a concurrent process. Therefore, 17 racemic (hetero) aromatic sec-alcohols with different substitutions in the aromatic ring have been converted into enantioenriched amines with good to excellent selectivities (90-99% ee) and conversion values (67-99%). The scalability of the process was also demonstrated when two different amine donors were used in the transamination step, such as isopropylamine and cis-2-buten-1,4-diamine. Satisfyingly, both sacrificial amine donors can shift the equilibrium toward the amine formation, leading to the corresponding isolated enantioenriched amines with good to excellent results.
Trading N and O. Part 3: Synthesis of 1,2,3,4-tetrahydroisoquinolines from α-hydroxy-β-amino esters
Davies, Stephen G.,Fletcher, Ai M.,Frost, Aileen B.,Kennedy, Matthew S.,Roberts, Paul M.,Thomson, James E.
, p. 2139 - 2163 (2016/04/09)
A range of enantiopure 1,2,3,4-tetrahydroisoquinolines have been prepared directly from α-hydroxy-β-amino esters. Activation of the α-hydroxy group upon treatment with Tf2O and 2,6-di-tert-butyl-4-methylpyridine promotes aziridinium formation,
