17272-83-2Relevant articles and documents
Method for preparing amine through catalytic reduction of nitro compound by cyclic (alkyl) (amino) carbene chromium complex
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Paragraph 0015, (2021/04/17)
The cyclic (alkyl) (amino) carbene chromium complex is prepared from corresponding ligand salt, alkali and CrCl3 and used for catalyzing pinacol borane to reduce nitro compounds in an ether solvent under mild conditions to generate corresponding amine. The method for preparing amine has the advantages of cheap and accessible raw materials, mild reaction conditions, wide substrate application range, high selectivity and the like, and is simple to operate.
Mimicking transition metals in borrowing hydrogen from alcohols
Banik, Ananya,Ahmed, Jasimuddin,Sil, Swagata,Mandal, Swadhin K.
, p. 8353 - 8361 (2021/07/02)
Borrowing hydrogen from alcohols, storing it on a catalyst and subsequent transfer of the hydrogen from the catalyst to anin situgenerated imine is the hallmark of a transition metal mediated catalyticN-alkylation of amines. However, such a borrowing hydrogen mechanism with a transition metal free catalytic system which stores hydrogen molecules in the catalyst backbone is yet to be established. Herein, we demonstrate that a phenalenyl ligand can imitate the role of transition metals in storing and transferring hydrogen molecules leading to borrowing hydrogen mediated alkylation of anilines by alcohols including a wide range of substrate scope. A close inspection of the mechanistic pathway by characterizing several intermediates through various spectroscopic techniques, deuterium labelling experiments, and DFT study concluded that the phenalenyl radical based backbone sequentially adds H+, H˙ and an electron through a dearomatization process which are subsequently used as reducing equivalents to the C-N double bond in a catalytic fashion.
Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
Zhao, Lixing,Hu, Chenyang,Cong, Xuefeng,Deng, Gongda,Liu, Liu Leo,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 1618 - 1629 (2021/01/25)
Transition metal catalysis that utilizes N-heterocyclic carbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC-Cr precatalyst, the addition of HBpin to nitro scaffolds leads to deoxygenation, allowing for the retention of various reducible functionalities and the compatibility of sensitive groups toward hydroboration, thereby providing a mild, chemoselective, and facile strategy to form anilines, as well as heteroaryl and aliphatic amine derivatives, with broad scope and particularly high turnover numbers (up to 1.8 × 106). Mechanistic studies, based on theoretical calculations, indicate that the CAAC ligand plays an important role in promoting polarity reversal of hydride of HBpin; it serves as an H-shuttle to facilitate deoxygenative hydroboration. The preparation of several commercially available pharmaceuticals by means of this strategy highlights its potential application in medicinal chemistry.
Regioselective Nitration of N-Alkyl Anilines using tert-Butyl Nitrite under Mild Condition
Chaudhary, Priyanka,Gupta, Surabhi,Muniyappan, Nalluchamy,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
, p. 104 - 119 (2019/01/08)
Regioselective ring nitration of N-alkyl anilines is reported using tert-butyl nitrite. The reactions proceed efficiently with a wide range of substrates providing synthetically useful N-nitroso N-alkyl nitroanilines in excellent yields which can be easily converted into N-alkyl phenylenediamines and N-alkyl nitroanilines using Zn-AcOH and HCl/MeOH, respectively.
Hexafluoro-2-propanol-assisted quick and chemoselective nitro reduction using iron powder as catalyst under mild conditions
Chen, Xu-Ling,Ai, Bai-Ru,Dong, Yu,Zhang, Xiao-Mei,Wang, Ji-Yu
supporting information, p. 3646 - 3649 (2017/08/23)
Hexafluoro-2-propanol as the promoter for the quick nitro reduction using a combination of iron powder and 2 N HCl aqueous solution is reported. This methodology has several positive features, as it is of room temperature, remarkably short reaction time. A wide range of substrates including those bearing reducible functional groups such as aldehyde, ketone, acid, ester, amide, nitrile, halogens, even allyl, propargyl and heterocycles are chemoselectively reduced in good to excellent yields, even on gram scale. Notably, the highly selective reduction of 3-nitrophenylboronic acid is achieved quantitatively. The reduction is also tolerant of common protecting groups, and aliphatic nitro compound, 1-nitrooctane can be reduced successfully.
Enantioselective epoxidation of unfunctionalized olefins by Jacobsen's catalyst immobilized on amino-modified ZnPS-PVPA
Huang, Jing,Iuo, Yan,Cai, Jiali
, p. 1539 - 1548 (2016/10/04)
Catalytic asymmetric epoxidation of alkenes is a powerful method for the synthesis of chiral organic compounds. A recyclable chiral Jacobsen's catalyst immobilized on ZnPS-PVPA on diamines gave high catalytic activity (conversion > 99%, ee > 99%) in the asymmetric epoxidations of unfunctionalized olefins. The synergistic effect of the support ZnPS-PVPA and the linkage as well as chiral salen Mn center contributed to the chirality of the product. The stability (recycled nine times) and the ease of use in large scale reactions (200 times scale) indicated a catalyst useful for industrial use.
Towards a general ruthenium-catalyzed hydrogenation of secondary and tertiary amides to amines
Cabrero-Antonino, Jose R.,Alberico, Elisabetta,Junge, Kathrin,Junge, Henrik,Beller, Matthias
, p. 3432 - 3442 (2016/05/19)
A broad range of secondary and tertiary amides has been hydrogenated to the corresponding amines under mild conditions using an in situ catalyst generated by combining [Ru(acac)3], 1,1,1-tris(diphenylphosphinomethyl)ethane (Triphos) and Yb(OTf)3. The presence of the metal triflate allows to mitigate reaction conditions compared to previous reports thus improving yields and selectivities in the desired amines. The excellent isolated yields of two scale-up experiments corroborate the feasibility of the reaction protocol. Control experiments indicate that, after the initial reduction of the amide carbonyl group, the reaction proceeds through the reductive amination of the alcohol with the amine arising from collapse of the intermediate hemiaminal.
The triflic acid-mediated cyclisation of N-benzylcinnamanilides
King, Frank D.,Caddick, Stephen
, p. 8592 - 8601 (2013/09/12)
N-Benzylcinnamanilides cyclise with triflic acid to form 1-benzyl-4-aryl-2,4-dihydro-1H-quinolin-2-ones and 2,5-diaryl-benzazepin-3-ones. The product ratio is determined by the preferred orientation of the amide and by the electronics of the substituents. With ortho-substituted anilides, N-debenzylation also occurs to give 4-aryl-2,4-dihydro-1H-quinoline-2-ones.
The iridium-catalyzed synthesis of symmetrically and unsymmetrically alkylated diamines under mild reaction conditions
Michlik, Stefan,Hille, Toni,Kempe, Rhett
scheme or table, p. 847 - 862 (2012/05/04)
An iridium catalyst - stabilized by an anionic P,N ligand - was used for the symmetrical and unsymmetrical monoalkylation of para-, meta-, and ortho-benzenediamines. Benzyl and aliphatic alcohols were used as alkylating reagents. 28 derivatives were synthesized. 14 of them are new compounds. Furthermore, the alkylation of the pharmacological important diamine Dapson (dapsone) is described. 14 dapsone derivatives were synthesized among them 9 new compounds. Copyright
Solid supported Pd(0): An efficient recyclable heterogeneous catalyst for chemoselective reduction of nitroarenes
Shil, Arun K.,Sharma, Dharminder,Guha, Nitul Ranjan,Das, Pralay
supporting information; experimental part, p. 4858 - 4861 (2012/09/08)
Solid supported palladium(0) (SS-Pd) catalyzed highly chemoselective reduction of nitroarenes to the corresponding anilines was accomplished under a milder reaction condition. This catalyst showed high compatibility with various reducing agents (NaBH4, Et3SiH, and NH2NH 2·H2O) and a large number of reducible functional groups such as sulfonamide, amides, carboxylic acid, ester, alcohol, halide, hetero cycle, nitrile, alkene, carbonyl, O-benzyl, and N-benzyl were tolerated. Most of the reactions were clean and high yielding. The SS-Pd catalyst could be recycled up to seven runs without significant loss of activity.
