- Selective Pd-catalyzed monoarylation of small primary alkyl amines through backbone-modification in ylide-functionalized phosphines (YPhos)
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Ylide-substituted phosphines have been shown to be excellent ligands for C-N coupling reactions under mild reaction conditions. Here we report studies on the impact of the steric demand of the substituent in the ylide-backbone on the catalytic activity. Two new YPhos ligands with bulky ortho-tolyl (pinkYPhos) and mesityl (mesYPhos) substituents were synthesized, which are slightly more sterically demanding than their phenyl analogue but considerably less flexible. This change in the ligand design leads to higher selectivities and yields in the arylation of small primary amines compared to previously reported YPhos ligands. Even MeNH2 and EtNH2 could be coupled at room temperature with a series of aryl chlorides in high yields.
- Rodstein, Ilja,Prendes, Daniel Sowa,Wickert, Leon,Paa?en, Maurice,Gessner, Viktoria H.
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p. 14674 - 14683
(2020/12/29)
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- Effect of heterocyclic ring on LnIII coordination, luminescence and extraction of diamides of 2,2′-Bipyridyl-6,6′-dicarboxylic acid
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We have synthesized and examined several complexes of lanthanides with diamides of 2,2′-bipyridyl-6,6′-dicarboxylic acid bearing various hetaryl-based side chains for the elucidation of the effect of the heterocycle on the structure and properties of the ligands. The multigram scale methods for the preparation of various N-alkyl-hetaryls and their diamides were developed. The solid state structure of 6-methyl-2-pyridylamide of 2,2′-bipyridyl-6,6′-dicarboxylic acid possesses a flat structurewhere the conformation is completely different fromthat previously observed forN-alkylated 2,2′-bipyridyl-6,6′-dicarboxamides and 2,6-pyridinedicarboxamides. The complexes of new ligands were synthesized and NMR and X-Ray studied their structure in solution and solid state. The results demonstrate that complexes possess the same structures both in solid state and in solution. Stability constants of the complexes were less when comparing with dimethyl-substituted diamides, but higher than for unsubstituted dianilide. Contrarily, the extraction ability of 2-pyridyl-diamide is significantly lower than for corresponding anilide. Specific interaction of extractant with solvent molecules, which is not available for electron-sink pyridine amides, can explain this. The luminescence of new Eu complexes was significantly higher than for all previously 2,2′-bipyridyl-6,6′-dicarboxamides and QY reaches 18%. Asymmetry ratios of Eu complexes were 25% higher when compared other complexes with 2,2′-bipyridyl-6,6′-dicarboxamides, which indicates large deviation from the inversion center.
- Borisova, Nataliya E.,Ivanov, Alexey V.,Kharcheva, Anastasia V.,Matveev, Petr I.,Patsaeva, Svetlana V.,Sumyanova, Tsagana B.,Surkova, Uliana V.
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- TRIAZOLOPYRIDINE COMPOUNDS AND METHODS FOR THE TREATMENT OF CYSTIC FIBROSIS
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The invention relates to a compound of Formula I or IA and methods of treating cystic fibrosis comprising the step of administering a therapeutically effective amount of a compound of Formula I or IA to a patient in need thereof:
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Paragraph 0088; 0089
(2016/05/02)
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- Palladium-catalyzed amination of aryl chlorides and bromides with ammonium salts
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We report the palladium-catalyzed coupling of aryl halides with ammonia and gaseous amines as their ammonium salts. The coupling of aryl chlorides and ortho-substituted aryl bromides with ammonium sulfate forms anilines with higher selectivity for the primary arylamine over the diarylamine than couplings with ammonia in dioxane. The resting state for the reactions of aryl chlorides is different from the resting state for the reactions of aryl bromides, and this change in resting states is proposed to account for a difference in selectivities for reactions of the two haloarenes.
- Green, Rebecca A.,Hartwig, John F.
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supporting information
p. 4388 - 4391
(2015/01/08)
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- Selective N-alkylation of amines using nitriles under hydrogenation conditions: Facile synthesis of secondary and tertiary amines
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Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH4OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.
- Ikawa, Takashi,Fujita, Yuki,Mizusaki, Tomoteru,Betsuin, Sae,Takamatsu, Haruki,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
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supporting information; experimental part
p. 293 - 304
(2012/02/01)
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- A facile N-monoalkylation of aminopyridines
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The N-monoalkylation of 2- or 3-aminopyridines by a carboxylic acid and sodium borohydride afforded the corresponding alkylaminopyridine under mild conditions in good yields. N-Alkylaminopyridines are important intermediate for preparing N-containing heterocycles, such as flytrap aminopyridinium-based anion hosts and pharmaceuticals.
- Tian, Zhongzhen,Li, Dongmei,Jiang, Zhaoxing,Li, Zhong
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p. 628 - 629,2
(2020/07/30)
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- Heteroaryl substituted bis-trifluoromethyl carbinols as malonyl-CoA decarboxylase inhibitors
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A series of heteroaryl-substituted bis-trifluoromethyl carbinols were prepared and evaluated as malonyl-CoA decarboxylase (MCD) inhibitors. Some thiazole-based derivatives showed potent in vitro MCD inhibitory activities and significantly increased glucos
- Cheng, Jie-Fei,Mak, Chi Ching,Huang, Yujin,Penuliar, Richard,Nishimoto, Masahiro,Zhang, Lin,Chen, Mi,Wallace, David,Arrhenius, Thomas,Chu, Donald,Yang, Guang,Barbosa, Miguel,Barr, Rick,Dyck, Jason R.B.,Lopaschuk, Gary D.,Nadzan, Alex M.
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p. 3484 - 3488
(2007/10/03)
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- Reductive and catalytic monoalkylation of primary amines using nitriles as an alkylating reagent
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(Chemical Equation Presented) A selective and catalytic mono-N-alkylation method of both aromatic and aliphatic amines using nitriles as an alkylating agent with Pd/C or Rh/C as a catalyst is described. This method is particularly attractive to provide an environmentally benign and applicable alkylation method of amines without using toxic and corrosive alkylating agents such as alkyl halides and carbonyl compounds.
- Sajiki, Hironao,Ikawa, Takashi,Hirota, Kosaku
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p. 4977 - 4980
(2007/10/03)
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- Slow anion exchange, conformational equilibria, and fluorescent sensing in venus flytrap aminopyridinium-based anion hosts
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The synthesis, anion binding, and conformational properties of a series of 3-aminopyridinium-based, tripodal, tricationic hosts for anions are described. Slow anion and conformational exchange on the 1H NMR time scale at low temperature, coupled with NMR titration, results in a high level of understanding of the anion-binding properties of the compounds, particularly with respect to significant conformational change resulting from induced fit complexation. Peak selectivity for halides, particularly Cl-, is observed. The approach has been extended to dipodal and tripodal podands based on 3-aminopyridinium "arms" containing photoactive anthracenyl moieties. The 1,3,5-tripodal host shows a remarkable selectivity for acetate over other anions, in contrast to the analogous unsubstituted tris(3-aminopyridinium) analogue, despite the fact that low-temperature 1H NMR experiments reveal a total of four acetate-binding conformations. Photodimerization of anthracene units results in the formation of potential fluorescent anion sensors.
- Wallace, Karl J.,Belcher, Warwick J.,Turner, David R.,Syed, Kauser F.,Steed, Jonathan W.
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p. 9699 - 9715
(2007/10/03)
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- Ruthenium complex-controlled catalytic N-mono- or N,N-dialkylation of heteroaromatic amines with alcohols
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Heteroaromatic amines were N-alkylated with primary alcohols at 150-200°C in the presence of a catalytic amount of various ruthenium complexes to give the corresponding monoalkylated and dialkylated amines in good to high yields. For example, 2-aminopyridine reacted with an excess of ethanol at 180°C for 20 h in the presence of dichlorotris(triphenylphosphine)ruthenium [RuCl2-(PPh3)3] to give 2-(ethylamino)pyridine (1) and 2-(diethylamino)pyridine (2) in 9% and 70% yields, respectively. On the other hand, when (η4-1,5-cyclooctadiene)(η 6-1,3,5-cyclooctatriene)ruthenium [Ru(cod)(cot)] was used as a catalyst, even in the presence of excess ethanol, 1 was obtained in 85% yield with high selectivity. The addition of tertiary phosphines and phosphites to Ru(cod)-(cot) increased the yield of the dialkylated amine.
- Watanabe, Yoshihisa,Morisaki, Yasuhiro,Kondo, Teruyuki,Mitsudo, Take-Aki
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p. 4214 - 4218
(2007/10/03)
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