66545-20-8Relevant academic research and scientific papers
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
supporting information, 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.
Tertiary amine alpha-position arylation method
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Paragraph 0098-0103, (2021/05/12)
The invention discloses a tertiary amine alpha-position arylation method, which comprises the following steps of: stirring tertiary amine and a cyanobenzene derivative which are used as raw materials in an organic solvent for a certain time by using inorg
Visible-Light-Induced α-Amino C-H Bond Arylation Enabled by Electron Donor-Acceptor Complexes
Xu, Chang,Shen, Fang-Qi,Feng, Gaofeng,Jin, Jian
supporting information, p. 3913 - 3918 (2021/05/29)
Enabled by electron donor-acceptor complexes, a novel visible-light-induced α-amino C-H bond arylation protocol, without a photoredox catalyst, has been disclosed. The protocol does not require any transition metal, oxidant, or exclusion of oxygen or moisture. A direct irradiation of the mixture of tertiary amines and benzonitriles with visible light in N,N-diethylethanamide in the presence of Cs2CO3 afforded α-arylated amines in good to excellent yields.
Triarylamine-based porous coordination polymers performing both hydrogen atom transfer and photoredox catalysis for regioselective α-amino C(sp3)-H arylation
Li, Hanning,Yang, Yang,Jing, Xu,He, Cheng,Duan, Chunying
, p. 8512 - 8520 (2021/06/28)
Direct functionalization of C(sp3)-H bonds in a predictable, selective and recyclable manner has become a central challenge in modern organic chemistry. Through incorporating different triarylamine-containing ligands into one coordination polymer, we present herein a heterogeneous approach to the combination of hydrogen atom transfer (HAT) and photoredox catalysis for regioselective C-H arylation of benzylamines. The different molecular sizes and coordination modes of the ligands, tricarboxytriphenylamine (H3TCA) and tris(4-(pyridinyl)phenyl)amine (NPy3), in one coordination polymer consolidate the triarylamine (Ar3N) moiety into a special structural intermediate, which enhances the chemical and thermal stability of the polymers and diminishes structural relaxation during the catalytic process. The inherent redox potentials of Ar3N moieties prohibit thein situformed Ar3N˙+to earn an electron from C(sp3)-H nucleophiles, but allow the abstraction of a hydrogen atom from C(sp3)-H nucleophiles, enabling the formation of the C(sp3)˙ radical and the cross-coupling reaction to proceed at the most electron-rich sites with excellent regioselectivity. The new heterogeneous photoredox HAT approach skips several interactions between transient species during the typical synergistic SET/HAT cycles, demonstrating a promising redox-economical and reagent-economical heterogeneous platform that has not been reported for α-amino C-H arylation to form benzylamine derivatives. Control experiments based on monoligand coordination polymers suggested that the mixed-ligand approach improved the photochemical and photophysical properties, providing important insight into rational design and optimization of recyclable photocatalysts for rapid access to complex bioactive molecules and late-stage functionalized pharmaceuticals.
Catalyst-free photodecarbonylation ofortho-amino benzaldehyde
Li, Lamei,Wang, Songping,Wei, Wentao,Yan, Ming,Zhou, Jingwei
, p. 3421 - 3426 (2020/06/25)
It is almost a consensus that decarbonylation of the aldehyde group (-CHO) needs to not only be mediated by transition metal catalysts, but also requires severe reaction conditions (high temperature and long reaction time). In this work, inspired by the “conformational-selectivity-based” design strategy, we broke this consensus and discovered a catalyst-free photodecarbonylation of the aldehyde group. It revealed that decarbonylation can be easily achieved with visible light irradiation by introducing a tertiary amine into theortho-position of the aldehyde group. A diverse array of tertiary amines is tolerated by our photodecarbonylation under mild conditions. Furthermore, the (QM) computations of the mechanism and the experiments on well-designed special substrates revealed that our photodecarbonylation depends on the conformational specificity of the aldehyde group and tertiary amine, and occurs through an unusual [1,4]-H shift and a subsequent [1,3]-H shift.
Coupling of C(sp3)-H bonds with C(sp2)-O electrophiles: mild, general and selective
Gui, Yong-Yuan,Liao, Li-Li,Sun, Liang,Zhang, Zhen,Ye, Jian-Heng,Shen, Guo,Lu, Zhi-Peng,Zhou, Wen-Jun,Yu, Da-Gang
supporting information, p. 1192 - 1195 (2017/02/05)
Herein is reported the mild and general coupling of amine/ether C(sp3)-H bonds with various kinds of C(sp2)-O electrophiles with high selectivity and efficiency. Valuable allylic/benzylic amines are generated in moderate to excellent yields. The utility of this transformation is demonstrated by a broad substrate scope (>50 examples), good functional group tolerance and facile product modification.
Base-promoted N-alkylation using formamides as the N-sources in neat water
Chen, Wen-Xin,Zhang, Cai-Yun,Shao, Li-Xiong
, p. 880 - 885 (2014/01/23)
An efficient catalyst-free, alternative method for the C-N bond formation reaction of alkyl electrophiles using formamides as the N-sources was achieved under mild conditions. The reaction possesses the advantages of a broad range of substrates scope and wide functional group tolerance. It should also be noted that this process was performed using the environmentally benign water as the sole solvent, and high yield can also be achieved in ten-gram scale.
Highly efficient amination in neat water of benzyl chlorides with dialkylformamides catalysed by N-heterocyclic carbene-palladium(II)-1- methylimidazole complex
Chen, Wen-Xin,Zhang, Cai-Yun,Lu, Jian-Mei
, p. 611 - 614 (2013/11/06)
Dialkylformamides are excellent N-sources in the amination of benzyl chlorides when catalysed by a NHC-Pd(II)-Im complex. In the presence of NaOH and the catalyst, variously substituted benzyl chlorides and five different dialkylformamides reacted smoothly to afford the corresponding N,N-dialkyl-benzylamines in good to almost quantitative yields in eco-friendly solvent water at 50 °C within 3 h.
Dynamics of anilinium radical α-heterolytic fragmentation processes. Electrofugal group, substituent, and medium effects on desilylation, decarboxylation, and retro-aldol cleavage pathways
Su, Zhuoyi,Mariano, Patrick S.,Falvey, Daniel E.,Yoon, Ung Chan,Oh, Sun Wha
, p. 10676 - 10686 (2007/10/03)
A single electron transfer (SET) photosensitization technique in conjunction with time-resolved, laser spectroscopy has been employed to generate and kinetically analyze decay processes of anilinium radicals derived by one-electron oxidation of α-anilinocarboxylates, β- anilinoalcohols, and α-anilinosilanes. In this manner, the rates of unimolecular decarboxylation of aniliniumcarboxylate radicals were determined to be in the range 106 - 107 s-1 and dependent upon solvent polarity, the nature of the metal cation, and substituents on the aniline ring, nitrogen, and α-carbon. In addition, kinetic analysis of base-induced retro-aldol fragmentations of cation radicals arising by SET oxidation of β- anilinoalcohols has shown that they occur with bimolecular rate constants which vary from 104 to 105 M-1 s1. These values are close to those for α-deprotonation reactions of related N,N-dialkylanilinium radicals. The retro-aldol fragmentation rates, like those for α-decarboxylation, also vary in a patterned way with changes in arene ring, nitrogen, and α- and β- carbon substituents. An investigation of the dynamics of methanol-promoted reactions of α-(trimethylsilyl)methyl-substituted anilinium radicals, has demonstrated that a change in the nitrogen substituent from alkyl to acyl causes an ca. 10-fold increase in the desilylation rate. Parallel photochemical studies have been conducted to gain chemical evidence to support assignment of the anilinium radical decay pathways in the LFP experiments and to demonstrate the preparative consequences of the kinetic results. First, clean formation of products derived by coupling of the (N- methylanilino)methyl radical in photochemical reactions of 1,4- dicyanobenzene with either tetra-n-butylammonium N-methyl-N-phenylglycinate or β-(N-methyl-N-phenyl)aminoethanol shows that the respective decarboxylation and retro-aldol cleavage processes occur with exceptionally high efficiencies. Second, in accord with the high rates observed for aminium radical decarboxylation and base-induced retro-aldol fragmentation, tethered cyclohexenone - α-aminocarboxylates and - β-aminoethanols undergo high- yielding SET-promoted photocyclization reactions under both direct and SET- sensitized conditions. Last, results which depict how the rates of aminium radical α-fragmentation correlate with quantum efficiencies of SET-promoted reactions of tertiary amines and amides have come from a study of photocyclization reactions of N-(aminoethyl)- and (amidoethyl)phthalimides. The quantum yields for these SET-promoted processes are observed to vary with the electrofugal group and nitrogen substituent in the manner predicted on the basis of the LFP-determined fragmentation rates.
