- Rh(III)-catalyzed synthesis of isoquinolines using the N-Cl bond of N-chloroimines as an internal oxidant
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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
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supporting information
(2020/03/10)
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- METHOD FOR THE HOMOGENEOUS CATALYTIC REDUCTIVE AMINATION OF CARBONYL COMPOUNDS
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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.
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Paragraph 0212; 0219-0221
(2018/07/29)
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- 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
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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.
- Issaraseriruk, Natthapol,Sritana-anant, Yongsak,Shitangkoon, Aroonsiri
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supporting information
p. 900 - 906
(2018/05/08)
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- Stereoselective amination of racemic sec-alcohols through sequential application of laccases and transaminases
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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.
- Martínez-Montero, Lía,Gotor, Vicente,Gotor-Fernández, Vicente,Lavandera, Iván
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p. 474 - 480
(2017/06/23)
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- Direct Synthesis of Primary Amines via Ruthenium-Catalysed Amination of Ketones with Ammonia and Hydrogen
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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
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supporting information
p. 358 - 363
(2016/04/26)
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- Compounds and methods for inhibiting phosphate transport
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Compounds having activity as phosphate transport inhibitors, more specifically, inhibitors of intestinal apical membrane Na/phosphate co-transport, are disclosed. The compounds have the following structure (I): including stereoisomers, pharmaceutically acceptable salts and prodrugs thereof, wherein X, Y, A, R1 and R2 are as defined herein. Methods associated with preparation and use of such compounds, as well as pharmaceutical compositions comprising such compounds, are also disclosed.
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Page/Page column 224; 225
(2016/05/02)
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- CATALYST COMPOUNDS
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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.
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Paragraph 0314; 0321
(2015/03/28)
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- Primary amines by transfer hydrogenative reductive amination of ketones by using cyclometalated IrIII catalysts
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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
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supporting information
p. 245 - 252
(2014/01/17)
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- CATALYST COMPOUNDS
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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.
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Paragraph 00163; 00170
(2013/11/05)
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- Regioselective hydroboration-oxidation and -amination of fluoro-substituted styrenes
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Hydroboration of fluorinated styrenes with common hydroborating agents results in polymerization. However, regioselective hydroboration has been achieved by utilizing iodoborane-dimethyl sulfide. A series of fluorinated β-phenethyl alcohols and amines were synthesized via this methodology.
- Ramachandran, P. Veeraraghavan,Madhi, Sateesh,O'Donnell, Martin J.
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p. 1252 - 1255
(2008/09/20)
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- Synthesis and structure-activity relationships of potential anticonvulsants based on 2-piperidinecarboxylic acid and related pharmacophores
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Using N-(2,6-dimethyl)phenyl-2-piperidinecarboxamide (1) and N-(α-methylbenzyl)-2-piperidinecarboxamide (2) as structural leads, a variety of analogues were synthesised and evaluated for anticonvulsant activity in the MES test in mice. In the N-benzyl series, introduction of 3-Cl, 4-Cl, 3,4-Cl2, or 3-CF3 groups on the aromatic ring led to an increase in MES activity. Replacement of the α-methyl group by either i-Pr or benzyl groups enhanced MES activity with no increase in neurotoxicity. Substitution on the piperidine ring nitrogen led to a decrease in MES activity and neurotoxicity, while reduction of the amide carbonyl led to a complete loss of activity. Movement of the carboxamide group to either the 3- or 4-positions of the piperidine ring decreased MES activity and neurotoxicity. Incorporation of the piperidine ring into a tetrahydroisoquinoline or diazahydrinone nucleus led to increased neurotoxicity. In the N-(2,6-dimethyl)phenyl series, opening of the piperidine ring between the 1- and 6-positions gave the active norleucine derivative 75 (ED50 = 5.8 mg kg-1, TD50 = 36.4 mg kg-1, PI = 6.3). Replacement of the piperidine ring of 1 by cycloalkane (cyclohexane, cyclopentane, and cyclobutane) resulted in compounds with decreased MES activity and neurotoxicity, whereas replacement of the piperidine ring by a 4-pyridyl group led to a retention of MES activity with a comparable PI. Simplification of the 2-piperidinecarboxamide nucleus of 1 into a glycinecarboxamide nucleus led to about a six-fold decrease in MES activity. The 2,6-dimethylanilides were the most potent compounds in the MES test in each group of compounds evaluated, and compounds 50 and 75 should be useful leads in the development of agents for the treatment of tonic-clonic and partial seizures in man.
- Ho, Bin,Michael Crider,Stables, James P
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p. 265 - 286
(2007/10/03)
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