- Cobalt-Catalyzed Deoxygenative Hydroboration of Nitro Compounds and Applications to One-Pot Synthesis of Aldimines and Amides
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The commercially available and bench-stable Co(acac)2 ligated with bis[(2-diphenylphosphino)phenyl] ether (dpephos) was employed for selective room temperature hydroboration of nitro compounds with HBPin (TOF up to 4615 h?1), tolerating halide, hydroxy, amino, ether, ester, lactone, amide and heteroaromatic functionalities. These reactions offered a direct access to a variety of N-borylamines RN(H)BPin, which were in situ treated with aldehydes and carboxylic acids to produce a series of aldimines and secondary carboxamides without the need for dehydrating and/or coupling reagents. Combination of these transformations in a sequential one-pot manner allowed for direct and selective synthesis of aldimines and secondary carboxamides from readily available and inexpensive nitro compounds.
- Gudun, Kristina A.,Hayrapetyan, Davit,Khalimon, Andrey Y.,Segizbayev, Medet,Slamova, Ainur,Zakarina, Raikhan
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- Method for biosynthesizing isopropylamine hydrochloride by laccase
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In order to achieve the purpose, the invention provides a method for biosynthesizing isopropylamine hydrochloride by laccase. The method comprises the following steps: by using isopropanol and ammonia water as initiators and laccase as a catalyst, carrying out two-step reaction to obtain isopropylamine hydrochloride. According to the invention, the degradation characteristics of laccase on amine and alcohol are utilized, and it is accidentally found that laccase has the function of synthesizing isopropylamine. Meanwhile, the method has the characteristics of mild reaction conditions, high yield, low energy consumption and the like. The method has no pollution to the environment, and is a green and environment-friendly synthetic route.
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Paragraph 0020-0033
(2021/04/14)
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- Green method for catalyzing reduction reaction of aliphatic nitro derivative
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The invention relates to a green method for catalyzing reduction reaction of aliphatic nitro derivatives. According to the method, non-transition metal compounds, namely triethyl boron and potassium tert-butoxide, are used as a catalytic system for the first time, an aliphatic nitro derivative and pinacolborane which is low in price and easy to obtain are catalyzed to be subjected to a reduction reaction under mild conditions, and an aliphatic amine hydrochloride product is synthesized after acidification with a hydrochloric acid aqueous solution. Compared with a traditional method, the method generally has the advantages that the catalyst is cheap and easy to obtain, operation is convenient, and reaction is safe. The selective reduction reaction of the aliphatic nitro derivative catalyzed by the non-transition metal catalyst and pinacol borane is realized for the first time, and the aliphatic amine hydrochloride product is synthesized through acidification treatment of the hydrochloric acid aqueous solution, so that a practical new reaction strategy is provided for laboratory preparation or industrial production.
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Paragraph 0005-0006; 0033-0036
(2021/07/31)
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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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- Direct Preparation of Amides from Amine Hydrochloride Salts and Orthoesters: A Synthetic and Mechanistic Perspective
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The conversion of a wide range of primary and secondary aliphatic and a few arylamine hydrochloride salts to their corresponding acetamides with trimethyl orthoacetate is described. Mechanistic studies using NMR and gas chromatography-mass spectrometry techniques indicate these reactions proceed via an O-methylimidate intermediate that undergoes in situ demethylation by chloride, affording the corresponding acetamides. Synthetically, this reaction represents a practical, high-yielding protocol with a simple workup for the rapid conversion of amine hydrochloride salts to acetamides.
- Di Grandi, Martin J.,Bennett, Caitlin,Cagino, Kristen,Muccini, Arnold,Suraci, Corey,Saba, Shahrokh
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supporting information
p. 2601 - 2607
(2015/11/28)
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- A catalytic version of hypervalent aryl-λ3-iodane-induced Hofmann rearrangement of primary carboxamides: Iodobenzene as an organocatalyst and m-chloroperbenzoic acid as a terminal oxidant
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The first catalytic version of hypervalent aryl-λ3- iodane-induced Hofmann rearrangement of primary carboxamides, which probably involves in situ generation of a tetracoordinated bis(aqua)(hydroxy)phenyl- λ3-iodane complex as an active oxidant from a catalytic amount of iodobenzene by the reaction with m-chloroperbenzoic acid in the presence of HBF4 in dichloromethane-water under mild conditions, was developed.
- Miyamoto, Kazunori,Sakai, Yuuta,Goda, Shunsuke,Ochiai, Masahito
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supporting information; experimental part
p. 982 - 984
(2012/02/04)
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- 1,3,2,4-Diazadiphosphetidines as ligand and base for palladium-catalyzed suzukimiyaura, sonogashirahagihara, and homocoupling reactions of aryl halides under heterogeneous conditions in water
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1,3,2,4-Diazadiphosphetidines as easily prepared, cheap, and air-stable P(III) containing ligands are successfully used for the efficient CC bond formation via SuzukiMiyaura, SonogashiraHagihara, and homocoupling reactions of aryl iodides, bromides, and chlorides. The reactions occur heterogeneously in refluxing water and the nitrogen atoms in these ligands behave as base to exclude the need to add internally base. The ligand together with its Pd(0) complex is easily separated by filtration and reused for several runs.
- Iranpoor, Nasser,Firouzabadi, Habib,Tarassoli, Abbas,Fereidoonnezhad, Masood
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scheme or table
p. 1367 - 1373
(2011/02/22)
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- Synthesis, spectral characterization and crystal structures of organophosphonic diamides: Pyramidal nitrogen centers and hydrogen bonding in [PhP(O)(NHtBu)2], [PhP(O)(NHDipp)2] (Dipp = 2,6-iPr2C6H3) and [tBuP(O)(NHiPr)2]
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Organophosphonic diamides of general formula [R1P(O)(NHR2)2] (1-8; R1 = Ph, Cy or tBu and R2 = Cy, iPr, tBu or Dipp) have been prepared by the addition of P,P′-dichloro(alkyl/aryl)phosphine oxide, R1P(O)Cl2, to a solution of primary amine in toluene. The synthesis of PhP(O)(NHtBu)2 (1) in high yield was achieved by slow oxidation of PhP(NHtBu)2 in air over several days. All new compounds have been characterized by elemental analysis and by IR, EI mass and NMR (1H and 31P) spectroscopy. The molecular structures of [PhP(O)(NHtBu)2] (1), [PhPO(NHDipp)2] (2) and [tBuP(O)(NHiPr)2] (7) have been determined by single crystal X-ray diffraction studies. The amido nitrogen atoms in 1, 2 and 7 show considerable deviation from the expected trigonal-planar geometry. The observed dihedral angles and the orientation of the nitrogen lone pair (l.p.) in these compounds point to the role of l.p.(N) → σ*(P-X) type negative hyperconjugative interactions in P-N multiple bonding. Compounds 1 and 7 form interesting polymeric structures in the solid state with the aid of N-H...O=P hydrogen bonding interactions while the presence of the very bulky Dipp substituent on nitrogen in 2 prevents the participation of the N-H protons in hydrogen bonding with phosphoryl oxygen atoms.
- Murugavel, Ramaswamy,Pothiraja, Ramasamy
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p. 968 - 974
(2007/10/03)
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- Hydrogenolysis of 1-Aminopyrazoles: Synthesis of Primary and Secondary Alkylamines
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The tautomerizable N-aminopyrazolone 9, the O-methyl 1 and N-methyl derivatives 4 were condensed with carbonyl compounds to give the alkenylaminopyrazoles 12, 2a-g and 5c, wich, under mild conditions, were hydrogenated to the corresponding alkylamino derivatives.The subesquent hydrogenation of the latter ones gave different results according to the structure of the starting material.The 5-methoxy-1-alkylaminopyrazoles 3a-g yielded the 5-methoxypyrazole 15 and the corresponding primary amines in good yields.On the contrary, N-methyl-1-alkylaminopyrazolone-5 6c gave 1-a lkylpyrazolone-3 8.
- Adembri, G.,Camparini, A.,Ponticelli, F.,Scotton, M.
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p. 321 - 326
(2007/10/02)
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- Aminations with O-Diphenylphosphinylhydroxylamine. A Critical Evaluation
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A critical evaluation is presented of the scope of amination reactions with O-diphenylphosphinylhydroxylamine (ODPH) as compared to those using hydroxylamine-O-sulfonic acid (HOSA).Aminations with ODPH of isopropyl, t-butyl and cyclohexyl carbanions derived from the corresponding Grignard reagents, gave the corresponding amines in 36, 34 and 50 percent yields, respectively.The amination with HOSA of the same carbanions under similar conditions was unsuccessful.The aminative quaternization of the tertiary nitrogen of pyridine and quinoline with ODPH proceeded with comparable yields to those obtained with HOSA.An improved one flask amination with ODPH of indole, skatole and carbazole was achieved in 52 - 62 percent yields.The amination under the same conditions using HOSA gave consistently lower yields.Several other amination reactions which have been reported for HOSA were unsuccessful using ODPH.The conclusion is reached that overall the ODPH reagent is much less versatile than HOSA.Nevertheless, in the aminations of NH groups of heterocyclic compounds ODPH appears to be superior to HOSA and is the reagent of choice, in particular, since the preparation of ODPH is much less harzardous than that of HOSA. - Keywords: Synthesis, O-Diphenylphosphinylhydroxylamine, Hydroxylamine-O-sulfonic Acid, N-Amino Derivatives, N-Amino Heterocyclic Compounds
- Sosnovsky, George,Purgstaller, Klaus
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p. 582 - 586
(2007/10/02)
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- Conversion of Alcohols into Primary Amines, a New Mitsunobu Version of Gabriel-type Synthesis
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Primaere und sekundaere Alkohole liefern die entsprechenden Amin-hydrochloride 3 mit guten Ausbeuten (60-85percent), wenn sie unter milden Bedingungen mit N-(Diethoxyphosphoryl)-carbamidsaeure-tert-butylester (1) in Gegenwart von Azodicarbonsaeure-diethylester/Triphenylphosphan umgesetzt und danach die entstandenen N-Alkyl-N-(diethoxyphosphoryl)carbamidsaeureester 2 mit gasfoermigem HCl gespalten werden.Die Stereochemie dieser Reaktion wird untersucht.
- Slusarska, Elzbieta,Zwierzak, Andrzej
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p. 402 - 405
(2007/10/02)
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- Lithiation of α-Nitrosaminoalkyl Ethers. Synthetic Equivalents of α-Primary Amino Carbanions
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Successful experiments directed toward the C-1 alkylation and hydroxyalkylation of primary amines are reported.Primary amines are converted into their N-nitroso-N-(1-methoxyethyl) derivatives, which are subsequently lithiated and condensed with various electrophiles, denitrosated, and hydrolyzed to produce the desired compounds in good to excellent yields.
- Saavedra, Joseph E.
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p. 2388 - 2392
(2007/10/02)
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- Caustic-free process for the production of monochloro-diamino-s-triazines
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A new and improved process is provided for preparing monochloro-diamino-s-triazines which are useful as herbicides. The process comprises reacting in a first stage cyanuric chloride and a selected monoalkylamine hydrochloride at elevated temperature to give a dichloro-monoalkylamino-s-triazine and reacting in a second stage this dichloro-monoalkylamino-s-triazine with an excess of a different monoalkylamine which may be introduced as a pure liquid, as gas or as a solution in water. The third stage of the process consists of an exchange whereby the monoalkylamine hydrochloride of the first stage and the free monoalkylamine of the second stage are generated. The process gives consistent yields in excess of 97% of monochloro-diamino-s-triazines. Because the process is caustic-free and due to the feasibility of recycling the excess of monoalkylamines employed, no serious effluent problems arise.
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- Amidoximether insecticides
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This invention is concerned with certain aryl amidoxime ethers of 3-phenoxybenzyl alcohol, which have insecticidal activity.
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