- Method for preparing amine through catalytic reduction of nitro compound by cyclic (alkyl) (amino) carbene chromium complex
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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.
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Paragraph 0015
(2021/04/17)
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- Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
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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.
- Zhao, Lixing,Hu, Chenyang,Cong, Xuefeng,Deng, Gongda,Liu, Liu Leo,Luo, Meiming,Zeng, Xiaoming
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supporting information
p. 1618 - 1629
(2021/01/25)
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- Ruthenium-Catalyzed Reductive Arylation of N-(2-Pyridinyl)amides with Isopropanol and Arylboronate Esters
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A new three-component reductive arylation of amides with stable reactants (iPrOH and arylboronate esters), making use of a 2-pyridinyl (Py) directing group, is described. The N-Py-amide substrates are readily prepared from carboxylic acids and PyNH2, and the resulting N-Py-1-arylalkanamine reaction products are easily transformed into the corresponding chlorides by substitution of the HN-Py group with HCl. The 1-aryl-1-chloroalkane products allow substitution and cross-coupling reactions. Therefore, a general protocol for the transformation of carboxylic acids into a variety of functionalities is obtained. The Py-NH2 by-product can be recycled.
- Ronson, Thomas O.,Renders, Evelien,Van Steijvoort, Ben F.,Wang, Xubin,Wybon, Clarence C. D.,Prokopcová, Hana,Meerpoel, Lieven,Maes, Bert U. W.
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supporting information
p. 482 - 487
(2019/01/04)
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- Syntheses, spectroscopy, electrochemistry, EPR, PXRD-structure and DFT/TD-DFT of bis[2-oxo-1-naphthaldehydato-κO,O’]copper(II)
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Reaction of N-2-(R-pyridyl)-2-hydroxy-1-naphthaldimine {R = H (HL1), 4-CH3 (HL2) and 6-CH3 (HL3)} with copper(II) nitrate provides the new complex of bis[2-oxo-1-naphthaldehydato-κO,O’]copper(II) (1) via in-situ hydrolysis of the Schiff base back to 2-hydroxy-1-naphthaldehyde (HL′). Elemental analyses reveal that there are no nitrogen atoms in the complex. X-ray diffraction (PXRD) data indicate that the complex is monoclinic with space group P21/a and Z = 2 and that the ligand acts as bidentate through O?O-chelate system forming a bis-complex with O2O2-coordination sphere around the copper(II) ion. Electrochemical results show two quasi-reversible one electron charge transfer processes attributed to [Cu(L′)2]2?/[Cu(L′)2]? and [Cu(L′)2]?/[Cu(L′)2] (L’ = deprotonated aldehyde) couples in acetonitrile. The magnetic data confirm the paramagnetic property of the complex with one unpaired electron in the metallic centre. The results suggest that the complex assumes a geometry between tetrahedral and square-planar supported by DFT calculations. Thermal analysis shows an irreversible phase transformation from solid to isotropic liquid phase. EPR spectrum in chloroform exhibits an isotropic pattern with four lines due to nuclear hyperfine splitting from the copper(II) ion with spin 3/2. The structural analyses, electrochemical and paramagnetic properties of these complexes explore greater interests for their use in the supramolecular chemistry.
- Enamullah, Mohammed,Joy, Baitul Alif,Islam, Mohammad Khairul
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- Copper(ii)-catalyzed c-n coupling of aryl halides and n-nucleophiles promoted by quebrachitol or diethylene glycol
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Herein, we report the natural ligand quebrachitol (QCT) as a promoter for a Cu(II) catalyst, which is highly effective for N-Arylation of various amines and related aryl halides. A series of diarylamine derivatives were obtained in high yields by using diethylene glycol (DEG) as both ligand and solvent. The C-N coupling reactions proceed under mild conditions and exhibit good functional group tolerance.
- Chen, Guoliang,Chen, Yuanguang,Du, Fangyu,Fu, Yang,Wu, Ying,Zhou, Qifan
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supporting information
p. 2161 - 2168
(2019/11/25)
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- Transition-metal-free access to 2-aminopyridine derivatives from 2-fluoropyridine and acetamidine hydrochloride
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Under catalyst-free conditions, an efficient method for the synthesis of 2-aminopyridine derivatives through the nucleophilic substitution and hydrolysis of 2-fluoropyridine and acetamidine hydrochloride has been developed. This amination uses inexpensive acetamidine hydrochloride as the ammonia source and has the advantages of a high yield, high chemoselectivity and wide substrate adaptability. The results suggest that other N-heterocycles containing fluorine substituents can also complete the reaction via these reaction conditions and yield the target products.
- Li, Yibiao,Huang, Shuo,Liao, Chunshu,Shao, Yan,Chen, Lu
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supporting information
p. 7564 - 7567
(2018/11/02)
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- Synthesis and purification method of 2-amino-4-methylpyridine
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The invention relates to the field of chemical synthesis, and concretely relates to a synthesis and purification method of 2-amino-4-methylpyridine. Crude 2-amino-4-methylpyridine is prepared from ethyl 2-(4-methylfuran)acetate through ring enlargement, hydroxyl group chlorination and dechlorination steps, the post-treatment process of the reaction in every step is easy to industrially operate, and doest not produce a difficultly-separated 2,6-diamino-4-methylpyridine byproduct; and the crude 2-amino-4-methylpyridine and an acid form a salt, the salt is dissolved in water, organic reagent extraction is carried out, the pH value of the obtained solution is adjusted to be more than 7, and the purity of the finally obtained product reaches 98% or above. The purification method as the advantages of simplicity, easiness in operation, low irritation of organic reagents used in the invention, and suitableness for industrial production.
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Paragraph 0022; 0042; 0043; 0046; 0047
(2017/09/01)
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- Peptide deformylase inhibitors
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The present invention relates to a compound of Formula (I): or a pharmaceutically acceptable salt thereof, corresponding pharmaceutical compositions, compound preparation and treatment methods directed to bacterial infections and inhibition of bacterial peptide deformylase (PDF) activity.
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Page/Page column
(2014/12/09)
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- PEPTIDE DEFORMYLASE INHIBITORS
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The present invention relates to a compound of Formula (I): or a pharmaceutically acceptable salt thereof, corresponding pharmaceutical compositions, compound preparation and treatment methods directed to bacterial infections and inhi-bition of bacterial peptide deformylase (PDF) activity
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Page/Page column
(2014/02/15)
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- A general and efficient 2-amination of pyridines and quinolines
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(Chemical Equation Presented) Pyridine N-oxides were converted to 2-aminopyridines in a one-pot fashion using Ts2O-t-BuNH2 followed by in situ deprotection with TFA. The amination proceeded in high yields, excellent 2-/4-selectivity, and with good functional group compatibility. 2-Amino (iso)quinolines were also obtained in the same manner. Combined with the simple oxidation of pyridines to pyridine N-oxides, this method provides a general and efficient way for amination of 2-unsubstituted pyridines.
- Yin, Jingjun,Xiang, Bangping,Huffman, Mark A.,Raab, Conrad E.,Davies, Ian W.
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p. 4554 - 4557
(2008/02/04)
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- SUBSTITUTED QUINAZOLINE DERIVATIVES AND THEIR USE AS INHIBITORS
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The use of a compound of formula (I) 1 or a salt, ester or amide thereof; where X is O, or S, S(O) or S(O)2, or NR6 where R6 is hydrogen or C1-6 alkyl,; R5 is an optionally substituted 5-membered heteroaromatic ring, R1, R2 ,R3, R4 are independently selected from various specified moieties, in the preparation of a medicament for use in the inhibition of aurora 2 kinase. Certain compounds are novel and these, together with pharmaceutical compositions containing them are also described and claimed
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- Substituted 2-aminopyridines as inhibitors of nitric oxide synthases.
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A series of substituted 2-aminopyridines was prepared and evaluated as inhibitors of human nitric oxide synthases (NOS). 4,6-Disubstitution enhanced both potency and specificity for the inducible NOS with the most potent compound having an IC50 of 28 nM.
- Hagmann,Caldwell,Chen,Durette,Esser,Lanza,Kopka,Guthikonda,Shah,MacCoss,Chabin,Fletcher,Grant,Green,Humes,Kelly,Luell,Meurer,Moore,Pacholok,Pavia,Williams,Wong
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p. 1975 - 1978
(2007/10/03)
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- N-aryl[1,2,4]triazolo[1,5-a]pyridine-2-sulfonamide herbicides
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Substituted N-aryl[1,2,4]triazolo[1,5-a]pyridine-2-sulfonamide compounds, such as N-(2,6-difluorophenyl)-5-methoxy-7-methyl[1,2,4]triazolo[1,5-a]pyridine-2-sulfonamide, N-(4-bromo-1-methyl-3-pyrazoly)-8-chloro-5-methoxy[1,2,4]triazolo[1,5-a]pyridine-2-sulfonamide, and N-(2-fluoro-4-methyl-3-pyridinyl)-8-ethoxy-6-chloro[1,2,4]triazolo[1,5-a]-pyridine-2-sulfonamide, were prepared by condensation of a 2-chlorosulfonyl[1,2,4]triazolo[1,5-a]pyridine compound with an aryl amine. The compounds prepared were found to possess excellent herbicidal activity on a broad spectrum of vegetation at low application rates.
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- Protection of Primary Amines as N-Substituted 2,5-Dimethylpyrroles
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Protection of primary amine group is achieved by incorporating it into an N-substituted 2,5-dimethylpyrrole system.The method affords protection against strong bases and nucleophiles, heating with concentrated alkali, standard mineral acid work-up conditions, and various other reagents.Phenyl-, pyridil-, thiazolyl-, and alkyl-amines have been studied.All give trisubstituted pyrroles in high yield (>80percent) by reaction with hexane-2,5-dione.The pyrroles from the first three types are stable to storage; even the N-alkyl compounds can be used without difficulty.Regeneration of the amine group, by treatment with hydrxylamine hydrochloride, is efficient (80percent yield) with the phenyl, pyridyl, and alkyl compounds but less satisfactory (60 - 65percent generally but down to 25percent in two cases) with the thiazolyl derivatives.
- Bruekelman, Stephen P.,Leach, (Miss) Susan E.,Meakins, G. Denis,Tirel, Malcolm D.
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p. 2801 - 2807
(2007/10/02)
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- Studies on 1,3-Benzoxazines. II. New Rearrangement Modes in the Reaction of 4-Chloro-2,2-dimethyl-2H-1,3-benzoxazine with Substituted Pyridine N-Oxides
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New rearrangement modes in the reaction of 4-chloro-2,2-dimethyl-2H-1,3-benzoxazine (1) with various α- and/or γ-substituted pyridine N-oxides are described.The benzoxazine moiety was introduced into the side chain and/or β-position of the pyridine ring, in addition to the α-position.Possible mechanism of the reactions are discussed.Keywords - 1,3-benzoxazine; picoline N-oxide; lutidine N-oxide; imidoyl chloride; rearrangement.
- Wachi, Kazuyuki,Terada, Atsusuke
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p. 3020 - 3028
(2007/10/02)
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- Separation of blood coagulation factors with non-activating polyelectrolytes
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Blood coagulation factors such as Factor VIII are separated from admixture with other blood proteins without producing activation of said coagulation factors by contacting with a water-insoluble, cross-linked polyelectrolyte copolymer of (a) C2-18 unsaturated monomer and (b) C4-12 unsaturated polycarboxylic acid or anhydride which is partially substituted at its free carboxyl or anhydride sites with amine-imides and in which substantially all the remaining free carboxyl or anhydride sites are blocked with alkoxyalkylamine to form alkoxyalkylimide units.
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