- Fluorescent Membrane Tension Probes for Early Endosomes
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Fluorescent flipper probes have been introduced recently to image membrane tension in live cells, and strategies to target these probes to specific membranes are emerging. In this context, early endosome (EE) targeting without the use of protein engineering is especially appealing because it translates into a fascinating transport problem. Weakly basic probes, commonly used to track the inside of acidic late endosomes and lysosomes, are poorly retained in EE because they are sufficiently neutralized in weakly acidic EE, thus able to diffuse out. Here, we disclose a rational strategy to target EE using a substituted benzylamine with a higher pKa value as a head group of the flipper probe. The resulting EE flippers are validated for preserved mechanosensitivity, ready for use in biology, particularly to elucidate the mechanics of endocytosis.
- Piazzolla, Francesca,Mercier, Vincent,Assies, Lea,Sakai, Naomi,Roux, Aurelien,Matile, Stefan
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Read Online
- Cp*Ir complex bearing a flexible bridging and functional 2,2′-methylenebibenzimidazole ligand as an auto-tandem catalyst for the synthesis of N-methyl tertiary amines from imines via transfer hydrogenation/N-methylation with methanol
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A Cp*Ir complex bearing a flexible bridging and functional 2,2′-methylenebibenzimidazole ligand was designed, synthesized, and found to be a general and efficient auto-tandem catalyst for the synthesis of N-methyl tertiary amines from imines via transfer hydrogenation/N-methylation with methanol as both hydrogen source and methylating reagent. In the presence of [Cp*Ir(2,2′-CH2BiBzImH2)Cl][Cl], a range of desirable products were obtained in high yields with nearly complete selectivities. The reaction is highly attractive due to the highly atom economy, and minimal consumption of chemicals and energy. Notably, this research exhibits new potential of metal–ligand bifunctional catalysts for the activation of methanol as C1 source for organic synthesis.
- Ai, Yao,Chen, Xiaozhong,Li, Feng,Liu, Peng,Yang, Chenchen,Yang, Jiazhi
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p. 325 - 334
(2021/10/07)
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- BF3·Et2O as a metal-free catalyst for direct reductive amination of aldehydes with amines using formic acid as a reductant
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A versatile metal- and base-free direct reductive amination of aldehydes with amines using formic acid as a reductant under the catalysis of inexpensive BF3·Et2O has been developed. A wide range of primary and secondary amines and diversely substituted aldehydes are compatible with this transformation, allowing facile access to various secondary and tertiary amines in high yields with wide functional group tolerance. Moreover, the method is convenient for the late-stage functionalization of bioactive compounds and preparation of commercialized drug molecules and biologically relevant N-heterocycles. The procedure has the advantages of simple operation and workup and easy scale-up, and does not require dry conditions, an inert atmosphere or a water scavenger. Mechanistic studies reveal the involvement of imine activation by BF3and hydride transfer from formic acid.
- Fan, Qing-Hua,Liu, Xintong,Luo, Zhenli,Pan, Yixiao,Xu, Lijin,Yang, Ji,Yao, Zhen,Zhang, Xin
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supporting information
p. 5205 - 5211
(2021/07/29)
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- Tertiary amine synthesis method
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The invention relates to the technical field of organic matters, and specifically relates to a tertiary amine synthesis method. Under the action of a catalyst, in the absence of solvent and alkali, primary amine, secondary amine, or a nitro derivative reacts with alcohol to prepare tertiary amine. The provided synthesis method has the advantages that no toxic solvent is used during the preparationprocess, the method is green and environmentally friendly, the atom utilization rate is high, the operation is simple, the application range of the functional groups and substrate is wide, and the yield of tertiary amine is high, in particular reactions between aliphatic amine and alcohol.
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Paragraph 0040-0045
(2019/01/24)
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- Iridium-Catalyzed Alkylation of Amine and Nitrobenzene with Alcohol to Tertiary Amine under Base- and Solvent-Free Conditions
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Herein, an efficient and green method for the selective synthesis of tertiary amines has been developed that involves iridium-catalyzed alkylation of various primary amines with aromatic or aliphatic alcohols. Notably, the catalytic protocol enables this transformation in the absence of additional base and solvent. Furthermore, the alkylation of nitrobenzene with primary alcohol to tertiary amine has also been achieved by the same catalytic system. Deuterium-labeling experiments and a series of control experiments were conducted, and the results suggested that an intermolecular borrowing hydrogen pathway might exist in the alkylation process.
- Li, Chao,Wan, Ke-Feng,Guo, Fu-Ya,Wu, Qian-Hui,Yuan, Mao-Lin,Li, Rui-Xiang,Fu, Hai-Yan,Zheng, Xue-Li,Chen, Hua
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p. 2158 - 2168
(2019/05/16)
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- Regioselective, Asymmetric Formal Hydroamination of Unactivated Internal Alkenes
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We report the regioselective and enantioselective formal hydroamination of unsymmetrical internal alkenes catalyzed by a copper catalyst ligated by DTBM-SEGPHOS. The regioselectivity of the reaction is controlled by the electronic effects of ether, ester, and sulfonamide groups in the homoallylic position. The observed selectivity underscores the influence of inductive effects of remote substituents on the selectivity of catalytic processes occurring at hydrocarbyl groups, and the method provides direct access to various 1,3-aminoalcohol derivatives with high enantioselectivity. A regio- and enantioselective formal hydroamination of unsymmetrical, unactivated internal alkenes occurs with a silane and hydroxylamine derivative. The regioselectivity is controlled by the electronic effects of ether, ester, and sulfonamide groups in the homoallylic position. This method provides direct access to 1,3-aminoalcohols with high enantioselectivity.
- Xi, Yumeng,Butcher, Trevor W.,Zhang, Jing,Hartwig, John F.
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p. 776 - 780
(2016/02/27)
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- N-alkylation of amines by homogeneous ruthenium complexes in the presence of free diphosphines
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Chemoselective N-alkylation of amines by ruthenium complexes in the presence of free diphosphine ligands under mild conditions is described. Octyl amine and aniline were chosen as aliphatic and aromatic amines to investigate the effect of different phosphines, reaction times, and temperature on conversion, as well as selectivity towards related secondary and tertiary amines. After optimization of the reaction conditions, this catalytic system was used for N-alkylation of other amines and has shown moderate to very good yields. The reaction products were monitored by GC-MS. The crystal structure of [Ru(NO3)2CO(PPh3)2] with a monodentate and a bidentate nitrate was determined by X-ray crystallographic analysis.
- Tamaddoni Jahromi, Bahareh,Kharat, Ali Nemati
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p. 3498 - 3508
(2014/01/06)
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- Selective alkylation of amines with alcohols by Cp*- iridium(III) half-sandwich complexes
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[Cp*Ir(Pro)Cl] (Pro = prolinato) was identified among a series of Cp*-iridium half-sandwich complexes as a highly reactive and selective catalyst for the alkylation of amines with alcohols. It is active under mild conditions in either toluene or water without the need for base or other additives, tolerates a wide range of alcohols and amines, and gives secondary amines in good to excellent isolated yields.
- Wetzel, Alexander,Woeckel, Simone,Schelwies, Mathias,Brinks, Marion K.,Rominger, Frank,Hofmann, Peter,Limbach, Michael
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supporting information
p. 266 - 269
(2013/03/14)
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- Coordination chemistry and catalytic activity of ruthenium(II) complexes containing a phospha-macrocyclic ligand
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Substitution of [RuCl2(CO)3(THF)], [RuCl 2(dmso)4] and [RuCl2(PPh3) 3] with a macrocyclic ligand, 2,3,4,5,6,7,8,9-octahydro-1,9-diphenyl- 1H-5,1,9-benzazadiphosphacyclo undecine (11-P2NH), provided [Ru(11-P2NH)Cl2(CO)] (3), [Ru(11-P2NH)Cl 2(dmso)] (4) and [Ru(11-P2NH)Cl2(CH 3CN)] (5), respectively. These complexes were characterized by elemental analyses as well as NMR spectroscopy. The structure of 3 was further confirmed by X-ray diffraction analysis. The octahedral geometry around the ruthenium center is in agreement with the Werner's "coordination" bonding concepts. The chelate rings of the macrocycle toward Ru(II) center adopting into chair conformations were revealed. Furthermore, these ruthenium complexes were found to be active for N-alkylation of dibenzylamine with alcohols.
- Lee, Chun-Chin,Huang, Hsiao-Ching,Liu, Shiuh-Tzung,Liu, Yi-Hung,Peng, Shie-Ming,Chen, Jwu-Ting
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p. 1024 - 1029
(2013/06/05)
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- Preparation of secondary and tertiary amines from nitroarenes and alcohols
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Various secondary amines were obtained selectively from the reaction of nitroarenes with primary alcohols in the presence of ruthenium(ii) complexes having phosphine-amine ligands as the catalyst. Secondary amines could be further alkylated with a primary alcohol using the same catalyst, but different conditions.
- Lee, Chun-Chin,Liu, Shiuh-Tzung
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supporting information; experimental part
p. 6981 - 6983
(2011/08/06)
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- Chemoselective debenzylation of N-benzyl tertiary amines with ceric ammonium nitrate
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Treatment of a range of N-benzyl tertiary amines with aqueous eerie ammonium nitrate results in N-debenzylation to afford the corresponding secondary amine. Chemoselective mono-W-debenzylation of N-benzyl tertiary amines is shown to occur in the presence of N-benzyl amides, O-benzyl ethers, O-benzyl esters, O-benzyl phenolates and 5-benzyl ethers. The Royal Society of Chemistry 2000.
- Bull, Steven D.,Davies, Stephen G.,Fenton, Carry,Mulvaney, Andrew W.,Shyam Prasad,Smith, Andrew D.
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p. 3765 - 3774
(2007/10/03)
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