4280-34-6Relevant academic research and scientific papers
Enantioselective Synthesis of N-Alkylamines through β-Amino C-H Functionalization Promoted by Cooperative Actions of B(C6F5)3and a Chiral Lewis Acid Co-Catalyst
Chang, Yejin,Cao, Min,Chan, Jessica Z.,Zhao, Cunyuan,Wang, Yuankai,Yang, Rose,Wasa, Masayuki
supporting information, p. 2441 - 2455 (2021/02/16)
We disclose a catalytic method for β-C(sp3)-H functionalization of N-alkylamines for the synthesis of enantiomerically enriched β-substituted amines, entities prevalent in pharmaceutical compounds and used to generate different families of chiral catalysts. We demonstrate that a catalyst system comprising of seemingly competitive Lewis acids, B(C6F5)3, and a chiral Mg- or Sc-based complex, promotes the highly enantioselective union of N-alkylamines and α,β-unsaturated compounds. An array of δ-amino carbonyl compounds was synthesized under redox-neutral conditions by enantioselective reaction of a N-alkylamine-derived enamine and an electrophile activated by the chiral Lewis acid co-catalyst. The utility of the approach is highlighted by late-stage β-C-H functionalization of bioactive amines. Investigations in regard to the mechanistic nuances of the catalytic processes are described.
Dehydrogenation/(3+2) Cycloaddition of Saturated Aza-Heterocycles via Merging Organic Photoredox and Lewis Acid Catalysis
Xiao, Teng-Fei,Zhang, Yi-Fan,Hou, Wen-Tao,Yan, Pen-Ji,Hai, Jun,Xu, Peng-Fei,Xu, Guo-Qiang
supporting information, p. 8942 - 8946 (2021/11/24)
Herein, we report a photoinduced dehydrogenation/(3+2) cycloaddition reaction by merging organic photoredox and Lewis acid catalysis, providing a straightforward and efficient approach for directly installing a benzofuran skeleton on the saturated aza-heterocycles. In this protocol, we also describe a novel organic photocatalyst (t-Bu-DCQ) with the advantages of a wider redox potential, easy synthesis, and a low price. Furthermore, the stepwise activation mechanism of dual C(sp3)-H bonds was demonstrated by a series of experimental and computational studies.
Organic photoredox catalytic α-C(sp3)-H phosphorylation of saturated: Aza -heterocycles
Yi, Ming-Jun,Xiao, Teng-Fei,Li, Wen-Hui,Zhang, Yi-Fan,Yan, Pen-Ji,Zhang, Baoxin,Xu, Peng-Fei,Xu, Guo-Qiang
supporting information, p. 13158 - 13161 (2021/12/16)
A metal-free C(sp3)-H phosphorylation of saturated aza-heterocycles via the merger of organic photoredox and Br?nsted acid catalyses was established under mild conditions. This protocol provided straightforward and economic access to a variety of valuable α-phosphoryl cyclic amines by using commercially available diarylphosphine oxide reagents. In addition, the D-A fluorescent molecule DCQ was used for the first time as a photocatalyst and exhibited an excellent photoredox catalytic efficiency in this transformation. A series of mechanistic experiments and DFT calculations demonstrated that this transformation underwent a sequential visible light photoredox catalytic oxidation/nucleophilic addition process.
I2/NaH2PO2-mediated deoxyamination of cyclic ethers for the synthesis of: N -aryl-substituted azacycles
Chen, Tieqiao,Huang, Tianzeng,Li, Chunya,Li, Dongyang,Lin, Ying,Liu, Long,Tang, Zhi,Zhang, Jingjing
supporting information, p. 21011 - 21014 (2021/12/04)
We have developed a protocol for efficient synthesis of N-aryl-substituted azacycles from aryl amines and cyclic ethers using I2/NaH2PO2 as the mediator. A diverse range of aryl amines and cyclic ethers undergo amination reaction to generate products in good to excellent yields with good functional group tolerance. This reaction can be easily scaled up to give N-aryl-substituted azacycles on a gram scale. Further chemical manipulation of the products enabled useful transformations of the quinoline ring, including bromination and acetylation. This journal is
Visible-Light-Enabled Direct Decarboxylative N-Alkylation
Arman, Hadi D.,Dang, Hang T.,Haug, Graham C.,Larionov, Oleg V.,Nguyen, Viet D.,Nguyen, Vu T.,Vuong, Ngan T. H.
supporting information, p. 7921 - 7927 (2020/04/10)
The development of efficient and selective C?N bond-forming reactions from abundant feedstock chemicals remains a central theme in organic chemistry owing to the key roles of amines in synthesis, drug discovery, and materials science. Herein, we present a dual catalytic system for the N-alkylation of diverse aromatic carbocyclic and heterocyclic amines directly with carboxylic acids, by-passing their preactivation as redox-active esters. The reaction, which is enabled by visible-light-driven, acridine-catalyzed decarboxylation, provides access to N-alkylated secondary and tertiary anilines and N-heterocycles. Additional examples, including double alkylation, the installation of metabolically robust deuterated methyl groups, and tandem ring formation, further demonstrate the potential of the direct decarboxylative alkylation (DDA) reaction.
Practical direct synthesis of: N -aryl-substituted azacycles from N -alkyl protected arylamines using TiCl4and DBU
Kang, Soosung,Kim, Hee-Kwon,La, Minh Thanh,Tran, Van Hieu
, p. 5008 - 5016 (2020/07/30)
A novel transformation of N-alkyl protected arylamines and cyclic ethers into N-aryl substituted azacycles is described. Alkyl groups have been used for the protection of amines in organic syntheses. In this synthesis, N-alkyl protected arylamines were reacted with cyclic ethers in the presence of TiCl4 and DBU, crucial reagents affording five- and six-membered azacycles. In particular, utilization of the novel TiCl4/DBU-mediated reaction allows various N-alkyl protected arylamines such as N-methyl-, N-ethyl-, N-isopropyl, and N-tert-butyl arylamines to be readily converted into N-aryl substituted azacycles in high yields. This practical approach using various N-alkyl arylamines leads to the efficient preparation of azacycles.
Organocatalytic Cascade β-Functionalization/Aromatization of Pyrrolidines via Double Hydride Transfer
An, Xiao-De,Li, Xian-Jiang,Liu, Qing,Shao, Chang-Lun,Xiao, Jian,Yang, Shuo,Zhou, Lan
supporting information, (2020/02/15)
An unprecedented cascade β-functionalization/aromatization reaction of N-arylpyrrolidines was established. A series of β-substituted arylpyrroles embedded with trifluoromethyl groups are provided directly from N-arylpyrrolidines. The deuterium-labeling experiments indicate that sequential double hydride transfer processes serve as the key steps in this transformation.
Palladium catalyzed hydrodefluorination of fluoro-(hetero)arenes
Gair, Joseph J.,Grey, Ronald L.,Giroux, Simon,Brodney, Michael A.
supporting information, p. 2482 - 2487 (2019/04/10)
Palladium catalyzed hydrodefluorination was developed for fine-tuning the properties of fluoro-(hetero)aromatic compounds. The robust reaction can be set up in air, requires only commercially available components, and tolerates a variety of heterocycles and functionalities relevant to drug discovery. Given the prevalence of fluorine incorporation around metabolic hotspots, the corresponding deuterodefluorination reaction may prove useful for converting fluorinated libraries to deuterated analogues to suppress the oxidative metabolism by kinetic isotope effects.
Redox-Neutral β-C(sp3)-H Functionalization of Cyclic Amines via Intermolecular Hydride Transfer
Zhou, Lan,Shen, Yao-Bin,An, Xiao-De,Li, Xian-Jiang,Li, Shuai-Shuai,Liu, Qing,Xiao, Jian
supporting information, p. 8543 - 8547 (2019/11/03)
Herein, we report the first redox-neutral and transition-metal-free β-C(sp3)-H functionalization of cyclic amines via a consecutive intermolecular hydride transfer process. A series of N-aryl pyrrolidines and N-aryl 1,2,3,4-tetrahydropyridines decorated with CF3 and carboxylic ester functionalities are directly accessed in good yields from pyrrolidines and piperidines. This work pushes forward the application of the intermolecular hydride transfer strategy in one-step assembly of molecular complexity.
Phosphoryl chloride-mediated solvent-free synthesis of N-aryl-substituted azacycles from arylamines and cyclic ethers
Tran, Van Hieu,La, Minh Thanh,Kim, Hee-Kwon
supporting information, p. 1860 - 1863 (2019/06/19)
A solvent- and metal-free protocol for preparation of N-aryl substituted azacycles from arylamines and cyclic ethers is described. In this method, the combination of POCl3 and DBU is crucial for conversion of arylamines and cyclic ethers to five- and six-membered azacycles. Without solvent, a variety of N-aryl-substituted, five-membered azacycles (pyrrolidines, 2-methylpyrrolidines, and piperidine) and six-membered azacycles (isoindolines and tetrahydroisoquinolines) are synthesized in high yields. This green method provides a sustainable and efficient approach for the preparation of azacycles from various cyclic ethers.
