620-40-6Relevant articles and documents
Helical structures of tribenzylamine supramolecular complexes with [CoCl4]2-/[CuCl4]2-, and conformational comparisons of tribenzylamine in different supramolecular complexes
Guan, Hong-Yu,Shao, Hui-De,Li, Lei,Jia, Jian-Ming,Guo, Fang
, p. 471 - 477 (2013)
The compound tribenzylamine (TBA) and its derivatives are a type of classical tripodal ligands in building up diversity of supramolecular arrays or networks. In the present contribution, we described two new supramolecular complexes 2[C21H22N+]·[CoCl 4]2-·(1) and 2[C21H22N +]·[CuCl4]2- (2) by reacting protonated TBA with CoCl2·6H2O/CuCl2·2H 2O. Different from previous TBA supramolecular complexes, these two supramolecular complexes were easier to obtain by grinding protonated TBA and CoCl2·6H2O/CuCl2·2H2O in an agate mortar than using conventional solution method. The two supramolecular complexes form fascinating 3D helical architectures, with two types of interwoven helical chains involved inside the structures. A comparison of the geometries of TBA in these two supramolecular complexes with the previously reported TBA supramolecular complexes shows that the significant differences are due to the conformation of the three arms of phenyl rings around the N center.
Synthesis and structural studies of tris-2-chlorobenzylamine and tris-2-bromobenzylamine
Chen, Qing,Buss, Carrie E.,Young Jr., Victor G.,Fox, Stephen
, p. 177 - 181 (2005)
The tris-2-chloro and 2-bromotribenzylamines are prepared from aqueous ammonia and 2-chlorobenzyl chloride and 2-bromobenzyl bromide, respectively, in ethanol. Recrystallization yielded colorless cubes of each product. The crystal structures are each solved in space group P1, and are isostructural. The tris-2-chloro compound, 1, has a = 7.4226(5) A, b = 9.0825(7) A, c = 14.529(1) A, α = 78.279(1)°, β = 82.389(1)°, γ = 84.661(1)°, and V = 948.41(12) A3 with Z = 2, and d calc = 1.368 Mg/m3. The tris-2-bromo analog, 2, has a = 7.6569(11) A, b = 9.0922(13) A, c = 14.614(2) A, α = 79.286(2)°, β = 81.777(2)°, γ = 85.401(2)°, and V = 987.9(2) A3 with Z = 2, and dcalc = 1.762 Mg/m 3. Lithium-halogen exchange experiments conducted in tetrahydrofuran at -78°C using n-butyl lithium revealed that no exchange occurred for the tris-2-chloro compound, but did occur for the tris-2-bromo analog to yield tribenzylamine upon quench and work-up.
Layered structures constructed by second-sphere coordination via N-H···Cl and C-H···Cl hydrogen bonding: Synthesis and crystal structures of tribenzylamine and [MCl6] (M=Sn, Re, and Te)
Guo, Fang,Lu, Na,Tong, Jian,Luan, Yu-Bo,Guo, Wen-Sheng
, p. 809 - 818 (2010)
A series of second-sphere coordination complexes of tribenzylamine (L1) and [MCI6] (M=Sn, Re, Te) have been synthesized and characterized by spectroscopic techniques (IR, NMR) and single-crystal X-ray diffraction. The main driving force for the encapsulation of [MCl6] and recognition with L1 is the second-sphere coordination of metal halides by the amide protons of the ligand via hydrogen bonding (N-H···Cl-M and C-H···Cl-M); new layered structures are described. Thermal stability and irreversible behavior of second-sphere coordination complexes [L2] 0.5[TeCl6]2- · HCl · (H3O)+ · 0.5H2O (L2=N,N,N′,N′-tetrabenzyl-ethylenediamine) in contact with water vapor are also described.
Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
Bera, Jitendra K.,Pandey, Pragati
, p. 9204 - 9207 (2021/09/20)
A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
Rapid Multialkylation of Aqueous Ammonia with Alcohols by Heterogeneous Iridium Catalyst under Simple Conditions
Yu, Han,Ma, Lin,Wada, Kenji,Kurihara, Ryohsuke,Feng, Qi,Uemura, Shinobu,Isoda, Kyosuke
, p. 3588 - 3593 (2021/07/02)
This paper reports the synthesis of tertiary and secondary amines from aqueous ammonia and benzylic alcohols by titania-supported iridium catalyst. It is a successful example of heterogeneous systems at moderate temperature without either additional solvent or high pressure. The catalytic system showed good tolerance to the atmosphere condition and performed rapidly to give tribenzylamine a yield of over 99 % within 6 hours in argon. The crystal structure of titania supports for iridium catalysts strongly affected their activity. The catalysis smoothly proceeded on larger scales. The catalyst could be easily reused and run at least for 5 cycles without significant loss of activity. The highly-dispersed iridium species of less than 2 nm in diameter would be responsible for the excellent catalytic activity. This catalyst is well applicable in multialkylation of aqueous ammonia with various primary and secondary benzylic alcohols.
Simplified preparation of a graphene-co-shelled Ni/NiO@C nano-catalyst and its application in theN-dimethylation synthesis of amines under mild conditions
Liu, Jianguo,Ma, Longlong,Song, Yanpei,Zhang, Mingyue,Zhuang, Xiuzheng
supporting information, p. 4604 - 4617 (2021/06/30)
The development of Earth-abundant, reusable and non-toxic heterogeneous catalysts to be applied in the pharmaceutical industry for bio-active relevant compound synthesis remains an important goal of general chemical research.N-methylated compounds, as one of the most essential bioactive compounds, have been widely used in the fine and bulk chemical industries for the production of high-value chemicals. Herein, an environmentally friendly and simplified method for the preparation of graphene encapsulated Ni/NiO nanoalloy catalysts (Ni/NiO@C) was developed for the first time, for the highly selective synthesis ofN-methylated compounds using various functional amines and aldehydes under easy to handle, and industrially applicable conditions. A large number of primary and secondary amines (more than 70 examples) could be converted to the correspondingN,N-dimethylamines with the participation of different functional aldehydes, with an average yield of over 95%. A gram-scale synthesis also demonstrated a similar yield when compared with the benchmark test. In addition, it was further proved that the catalyst could easily be recycled because of its intrinsic magnetism and reused up to 10 times without losing its activity and selectivity. Also, for the first time, the tandem synthesis ofN,N-dimethylamine products in a one-pot process, using only a single earth-abundant metal catalyst, whose activity and selectivity were more than 99% and 94%, respectively, for all tested substrates, was developed. Overall, the advantages of this newly developed method include operational simplicity, high stability, easy recyclability, cost-effectiveness of the catalyst, and good functional group compatibility for the synthesis ofN-methylation products as well as the industrially applicable tandem synthesis process.
Reduction of Amides to Amines with Pinacolborane Catalyzed by Heterogeneous Lanthanum Catalyst La(CH2C6H4NMe2- o)3@SBA-15
Guo, Chenjun,Zhang, Fangcao,Yu, Chong,Luo, Yunjie
supporting information, p. 13122 - 13135 (2021/08/31)
Hydroboration of amides is a useful synthetic strategy to access the corresponding amines. In this contribution, it was found that the supported lanthanum benzyl material La(CH2C6H4NMe2-o)3@SBA-15 was highly active for the hydroboration of primary, secondary, and tertiary amides to amines with pinacolborane. These reactions selectively produced target amines and showed good tolerance for functional groups such as -NO2, -halogen, and -CN, as well as heteroatoms such as S and O. This reduction procedure exhibited the recyclable and reusable property of heterogeneous catalysts and was applicable to gram-scale synthesis. The reaction mechanisms were proposed based on some control experiments and the previous literature. This is the first example of hydroborative reduction of amides to amines mediated by heterogeneous catalysts.
BF3·Et2O as a metal-free catalyst for direct reductive amination of aldehydes with amines using formic acid as a reductant
Fan, Qing-Hua,Liu, Xintong,Luo, Zhenli,Pan, Yixiao,Xu, Lijin,Yang, Ji,Yao, Zhen,Zhang, Xin
, p. 5205 - 5211 (2021/07/29)
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.
Reductive Alkylation of Azides and Nitroarenes with Alcohols: A Selective Route to Mono- And Dialkylated Amines
Borthakur, Ishani,Joshi, Abhisek,Kundu, Sabuj,Maji, Milan
, (2021/12/27)
Herein, we demonstrated an efficient protocol for reductive alkylation of azides/nitro compounds via a borrowing hydrogen (BH) method. By following this protocol, selective mono- and dialkylated amines were obtained under mild and solvent-free conditions. A series of control experiments and deuterium-labeling experiments were performed to understand this catalytic process. Mechanistic studies suggested that the Ir(III)-H was the active intermediate in this reaction. KIE study revealed that the breaking of the C-H bond of alcohol might be the rate-limiting step. Notably, this solvent-free strategy disclosed a high TON of around 5600. Based on kinetic studies and control experiments, a metal-ligand cooperative mechanism was proposed.
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
Ai, Yao,Chen, Xiaozhong,Li, Feng,Liu, Peng,Yang, Chenchen,Yang, Jiazhi
, p. 325 - 334 (2021/10/07)
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.
