112790-02-0Relevant academic research and scientific papers
Fluorescence of Cyclopropenium Ion Derivatives
Belding, Lee,Guest, Matt,Le Sueur, Richard,Dudding, Travis
, p. 6489 - 6497 (2018)
The synthesis of cyclopropenium-substituted amino compounds and analysis of their photophysical properties is described. Systematic structural modifications of these derivatives lead to measurable and predictable changes in molar extinction coefficients, quantum yields, and Stokes shifts. Using time-dependent density functional theory (TD-DFT) calculations, the origin of these trends was traced to internal charge transfer (ICT) coupled with ensuing structural reorganization for select naphthalene functionalized derivatives. Associated with this structural reorganization was an inward gearing of the cyclopropenium ring and twisting of the peri-NMe2 group into coplanarity with the naphthalene ring system. Further, reinforcement of an intramolecular H-bond (IMHB) in the excited state of these derivatives alludes to the importance of photoinduced H-bonding in this new class of cyclopropenium based fluorophores.
Highly Twisted N,N-Dialkylamines as a Design Strategy to Tune Simple Aromatic Hydrocarbons as Steric Environment-Sensitive Fluorophores
Sasaki, Shunsuke,Suzuki, Satoshi,Sameera,Igawa, Kazunobu,Morokuma, Keiji,Konishi, Gen-Ichi
, p. 8194 - 8206 (2016)
The steric-environment sensitivity of fluorescence of 9,10-bis(N,N-dialkylamino)anthracenes (BDAAs) was studied experimentally and theoretically. A new design strategy to tune simple aromatic hydrocarbons as efficient aggregation-induced emission (AIE) luminogens and molecular rotors is proposed. For a variety of BDAAs, prominent Stokes shifts and efficient solid-state fluorescence were observed. Calculations on BDAA-methyl suggested that in the ground state (S0) conformations, the pyramidal amine groups are highly twisted, so that their lone-pair orbitals cannot conjugate with the anthracene π orbitals. Fluorescence takes place from the S1 minima, in which one or both amine groups are planarized. The stability of the S1 excited state minima as well as destabilization of the S0 state is the origin of large Stokes shift. Experimental measurement of the nonadiabatic transition rate suggests that para disubstitution by dialkylamino (or strongly electron-donating) groups is a key for fast internal conversion. Minimum energy conical intersection (MECI) between S1 and S0 states was found to have a Dewar-benzene like structure. Although this can be reached efficiently in liquid phase for fast internal conversion, a large amplitude motion is required to reach this MECI, which is prohibited in the solid state and caused efficient AIE. This strategy is used to find experimentally that naphthalene analogues are also efficient AIE luminogens. The flexibility of alkyl chains on amino groups is also found to be important for allowed charge-transfer transition. Thus, three points [(1) highly twisted N,N-dialkylamines, (2) substitution at the para positions, (3) with flexible alkyl groups] were proposed for activation of small aromatic hydrocarbons.
1,8-Disubstituted naphthalenes by directed metalation and subsequent lithium-manganese exchange, including copper catalysis
Kiefl,Mannschreck
, p. 1033 - 1037 (1995)
Directed lithiation of 1-dimethylamino- and 1-methoxynaphthalene, followed by Li-Mn exchange and reaction with electrophiles, provides regioselective syntheses of previously unknown racemic thioamides 2, 11 and 12, and ketones 5-8.
SnCl2 mediated efficient N,N-dialkylation of azides to tertiary-amine via potential stannaimine intermediate
Roy, Ujjal Kanti,Roy, Sujit
, p. 1525 - 1530 (2006)
A base free one-pot conversion of azides to N,N-dialkylamine is described. A two-step reaction pathway has been postulated invoking the intermediacy of stannaimine. This new carbon-nitrogen bond formation strategy adds to the repertoire of tin(II) chemistry.
C8-H bond activation vs. C2-H bond activation: From naphthyl amines to lactams
Shi, Renyi,Lu, Lijun,Xie, Hangyu,Yan, Jingwen,Xu, Ting,Zhang, Hua,Qi, Xiaotian,Lan, Yu,Lei, Aiwen
, p. 13307 - 13310 (2016)
Pd-catalyzed selective amine-oriented C8-H bond functionalization/N-dealkylative carbonylation of naphthyl amines has been achieved. The amine group from dealkylation is proposed to be the directing group for promoting this process. It represents a straightforward and easy method to access various biologically important benzo[cd]indol-2(1H)-one derivatives.
Conformational Studies by Dynamic NMR. 37. Monitoring the Stereomutations of Symmetric Amines by Means of a Chiral Auxiliary Agent
Casarini, D.,Davalli, S.,Lunazzi, L.,Macciantelli, D.
, p. 4616 - 4619 (1989)
The chiral auxiliary agent (R)-l-2,2,2-trifluoro-1-(9-anthryl)ethanol was used to monitor the exchange between the enantiotopomers of symmetric amines lacking diastereotopic probes.The free energies of activation for stereomutations involving both C-N rotation and N-inversion processes were measured by line-shape simulation of the low-temperature NMR spectra.The effect of the chiral alcohol upon the barriers has also been evaluated, thus allowing one to compare these data with those of other amines where the stereomutations had been detected in achiral environment.The existence of steric deceleration for the exchange between enantiotopomers related by torsion and of steric acceleration for enantiotopomers related by N-inversion has been also verified.The highest N-inversion barrier observed in a simple noncyclic trialkyl amine (8.6 kcal mol-1 for Me2NEt) could thus be measured.
Synthesis, structure, and reactivity of disilanes containing one neutral [4 + 2]-coordinate silicon center
Tamao, Kohei,Asahara, Masahiro,Kawachi, Atsushi,Toshimitsu, Akio
, p. 479 - 486 (2002)
[4 + 2]-Coordinate disilanes containing two 8-dimethylamino-1-naphthyl (8-Me2N-1-Np) groups on the same silicon atom, (8-Me2N-1-Np)2XSi-SiMe3, where X = F, OH, OEt, and H, are prepared. The X-ray structures of t
Dirhodium-Catalyzed Chemo-and Site-Selective C-H Amidation of N, N-Dialkylanilines
Chen, Gong,Arai, Kenta,Morisaki, Kazuhiro,Kawabata, Takeo,Ueda, Yoshihiro
supporting information, p. 728 - 732 (2021/01/18)
A method for dirhodium-catalyzed C(sp 3)-H amidation of N, N-dimethylanilines was developed. Chemoselective C(sp 3)-H amidation of N-methyl group proceeded exclusively in the presence of C(sp 2)-H bonds of the electron-rich aromatic ring. Site-selective C(sp 3)-H amidation proceeded exclusively at the N-methyl group of N-methyl-N-Alkylaniline derivatives with secondary, tertiary, and benzylic C(sp 3)-H bonds α to a nitrogen atom.
Preparation method of N-alkylated derivative of primary amine compound
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Paragraph 0021; 0047, (2021/07/09)
The invention relates to a preparation method of an N-alkylated derivative of a primary amine compound. The method comprises the following steps: uniformly mixing a primary amine compound, an alcohol compound and a catalyst in a reactor, and heating to react for a period of time to generate an N-alkylated substituted tertiary amine compound; wherein the catalyst is a copper-cobalt bimetallic catalyst, and the carrier of the catalyst is Al2O3. According to the method, alcohol is adopted as an alkylating reagent and is low in price and easy to obtain, a byproduct is water, no pollution is caused to the environment, and the overall reaction atom economy is high; the catalyst is simple in preparation method, low in cost, high in reaction activity and good in structural stability; meanwhile, by using the copper-cobalt bimetallic catalyst, the use of strong base additives can be avoided, and the requirement on reaction equipment is low; and the reaction post-treatment is convenient, and the catalyst can be recycled and is environment-friendly.
Additive-freeN-methylation of amines with methanol over supported iridium catalyst
Liu, Xiang,Loh, Teck-Peng,Qiang, Wenwen,Wang, Jing,Ye, Sen,Zhu, Longfei
, p. 3364 - 3375 (2021/06/06)
An efficient and versatile zinc oxide-supported iridium (Ir/ZnO) catalyst was developed to catalyze the additive-freeN-methylation of amines with methanol. Mechanistic studies suggested that the high catalytic reactivity is rooted in the small sizes (1.4 nm) of Ir nanoparticles and the high ratio (93%) of oxidized iridium species (IrOx, Ir3+and Ir4+) on the catalyst. Moreover, the delicate cooperation between the IrOxand ZnO support also promoted its high reactivity. The selectivity of this catalyticN-methylation was controllable between dimethylation and monomethylation by carefully tuning the catalyst loading and reaction solvent. Specifically, neat methanol with high catalyst loading (2 mol% Ir) favored the formation ofN,N-dimethylated amine, while the mesitylene/methanol mixture with low catalyst loading (0.5 mol% Ir) was prone to producing mono-N-methylated amines. An environmentally benign continuous flow system with a recycled mode was also developed for the efficient production ofN-methylated amines. With optimal flow rates and amine concentrations, a variety ofN-methylamines were produced with good to excellent yields in this Ir/ZnO-based flow system, providing a starting point for the clean and efficient production ofN-methylamines with this cost-effective chemical process.
