- Secondary amine derivative synthesized through rare earth catalysis, and preparation method thereof
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The invention discloses a secondary amine derivative synthesized through rare earth catalysis, and a preparation method thereof. According to the preparation method, the secondary amine derivative isprepared by carrying out a reaction on reactants of secondary amide and pinacol borane; a rare earth catalyst bis(trimethylsilyl) amino yttrium is added; the reaction temperature is 100-140 DEG C, andthe reaction time is 20-25 h; the whole reaction is carried out under a normal pressure, and the reaction conditions are mild, easy to achieve and safe; the method is simple and convenient to operateand high in reaction selectivity, can directly synthesize the target product without intermediate product separation, can obtain the target product only through a reaction under a normal pressure, issimple in reaction process, has the yield of 90% at most, substantially simplifies the process engineering, reduces the energy consumption, and has high yield; the reaction raw materials are stable and easy to store; a series of secondary amine derivatives can be prepared; and the method has high substrate universality so as to provide the good guarantee for development of related substances related to secondary amine derivatives, and is suitable for large-scale application and popularization.
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Paragraph 0091; 0092; 0093; 0094; 0095; 0096; 0097
(2020/03/12)
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- Homoleptic Bis(trimethylsilyl)amides of Yttrium Complexes Catalyzed Hydroboration Reduction of Amides to Amines
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Homoleptic lanthanide complex Y[N(TMS)2]3 is an efficient homogeneous catalyst for the hydroboration reduction of secondary amides and tertiary amides to corresponding amines. A series of amides containing different functional groups such as cyano, nitro, and vinyl groups were found to be well-tolerated. This transformation has also been nicely applied to the synthesis of indoles and piribedil. Detailed isotopic labeling experiments, control experiments, and kinetic studies provided cumulative evidence to elucidate the reaction mechanism.
- Ye, Pengqing,Shao, Yinlin,Ye, Xuanzeng,Zhang, Fangjun,Li, Renhao,Sun, Jiani,Xu, Beihang,Chen, Jiuxi
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p. 1306 - 1310
(2020/02/22)
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- A BEt3-Base catalyst for amide reduction with silane
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Reported herein is the development of a simple but practical catalytic system for the selective reduction of amides with hydrosilane or hydrosiloxane. Low-cost and readily available triethylborane (1.0 M in THF), in combination with a catalytic amount of an alkali metal base, was found to catalyze the reduction of all three amide classes (tertiary, secondary, and primary amides) to form amines under mild conditions. In addition, the selective transformation of secondary amides to aldimines and primary amides to nitriles can also be achieved by using a proper combination of BEt3 and base. The scope of these BEt3-base-catalyzed amide hydrosilylation reactions has been explored in depth. Preliminary results of mechanistic studies suggest a modified Piers' silane Si-H···B activation mode wherein the hydride abstraction by BEt3 is promoted by the coordination of an alkoxide or hydroxide anion to the Si center.
- Yao, Wubing,Fang, Huaquan,He, Qiaoxing,Peng, Dongjie,Liu, Guixia,Huang, Zheng
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- A BEt3-Base Catalyst for Amide Reduction with Silane
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Reported herein is the development of a simple but practical catalytic system for the selective reduction of amides with hydrosilane or hydrosiloxane. Low-cost and readily available triethylborane (1.0 M in THF), in combination with a catalytic amount of an alkali metal base, was found to catalyze the reduction of all three amide classes (tertiary, secondary, and primary amides) to form amines under mild conditions. In addition, the selective transformation of secondary amides to aldimines and primary amides to nitriles can also be achieved by using a proper combination of BEt3 and base. The scope of these BEt3-base-catalyzed amide hydrosilylation reactions has been explored in depth. Preliminary results of mechanistic studies suggest a modified Piers' silane Si-H···B activation mode wherein the hydride abstraction by BEt3 is promoted by the coordination of an alkoxide or hydroxide anion to the Si center.
- Yao, Wubing,Fang, Huaquan,He, Qiaoxing,Peng, Dongjie,Liu, Guixia,Huang, Zheng
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p. 6084 - 6093
(2019/05/24)
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- Zinc-catalyzed chemoselective reduction of tertiary and secondary amides to amines
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General and convenient procedures for the catalytic hydrosilylation of secondary and tertiary amides under mild conditions have been developed. In the presence of inexpensive zinc catalysts, tertiary amides are easily reduced by applying monosilanes. Key to success for the reduction of the secondary amides is the use of zinc triflate and disilanes with dual Si-H moieties. The presented hydrosilylations proceed with excellent chemoselectivity in the presence of sensitive ester, nitro, azo, nitrile, olefins, and other functional groups, thus making the method attractive for organic synthesis.
- Das, Shoubhik,Addis, Daniele,Junge, Kathrin,Beller, Matthias
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experimental part
p. 12186 - 12192
(2011/11/07)
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- Reductive amination using ammonia borane
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A variety of primary, secondary, and tertiary amines were prepared in 84-95% yields using ammonia borane for the reductive amination of aldehydes and ketones in the presence of titanium isopropoxide.
- Veeraraghavan Ramachandran,Gagare, Pravin D.,Sakavuyi, Kaumba,Clark, Paul
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experimental part
p. 3167 - 3169
(2010/08/05)
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- Novel substituted diamine derivatives useful as motilin antagonists
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The present invention relates to novel substituted diamine derivatives for the formula wherein R1, R2, R3, R4, X1, X2, X3, X4, A, Y and n are as described in the speci
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- A one-pot aza-Wittig based solution and polymer supported route to amines
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This paper presents a high yielding one-pot solution phase and polymer supported synthesis of a range of primary and secondary amines starting from azides and aldehydes. The synthesis utilises a tandem process which begins with an aza-Wittig reaction between the aldehyde and an iminophosphorane, followed by reduction, or organometallic 1,2-addition reaction, of the resultant imine. The requisite iminophosphoranes were accessed using the highly efficient Staudinger reaction between the azide starting material and a phosphine. The process was applicable to the solid phase by the use of polymer supported iminophosphoranes and polymer supported cyanoborohydride.
- Hemming,Bevan,Loukou,Patel,Renaudeau
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p. 1565 - 1568
(2007/10/03)
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- A mild, convenient, and inexpensive method for converting imines into amines: Tin-catalyzed reduction with polymethylhydrosiloxane (PMHS)
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We have developed a mild, convenient, and inexpensive protocol for reducing imines to amines. Thus, treatment of any of a wide array of imines with catalytic n-butyltris(2-ethylhexanoate)tin and stoichioimetric polymethylhydrosiloxane (PMHS) in ethanol at room temperature cleanly affords the desired secondary amine product. Alkyl bromides, alkynes, epoxides, esters, nitriles, and olefins are inert toward these reduction conditions, whereas aldehydes, ketones, and nitro compounds are not.
- Lopez, Rosa M.,Fu, Gregory C.
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p. 16349 - 16354
(2007/10/03)
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- Reduction of imines via titanium-catalyzed hydromagnesation
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We have recently discovered that imines can be reduced to amines via a titanium catalyzed hydromagnesation reaction. These reactions employ n-BuMgCl (1.2 eq) as the stoichiometric reducing agent and Cp2TiCl2 (3-5 mol%) as a catalyst. Reactions are run under nitrogen at ambient temperature and pressure. For most aldimine and cyclic ketimine substrates amine products are obtained in yields ranging from 69-94%. The reaction is not tolerant of bulky nitrogen substituents or primary enolizable protons on the imine substrate.
- Amin, Sk. Rasidul,Crowe, William E.
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p. 7487 - 7490
(2007/10/03)
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- Bimolecular Nucleophilic Substitution (SN2) Reactions of Neopentyl Arenesulfonates with Anilines and Benzylamines in Methanol
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Bimolecular nucleophilic substitution (SN2) reactions of neopentyl arenesulfonates with anilines and benzylamines in methanol at 55.0 deg C are reported.The tightness of the transition state (TS) is similar to that for other typical SN2 processes at a primary alkyl carbon centre based on the magnitude of the cross-interaction constant ρxz (0.30) between the substituents in the nucleophile (X) and leaving group (Z).The TS variation is in accord with that predicted by the potential energy surface diagram, which in turn is consistent with the positive sign of ρxz; a later TS is obtained with a weaker nucleophile and nucleofuge.Taft's polar substituent constant, ?*, for the trimethylsilyl group is estimated to be -0.48 by using a factor of 1.875 for the fall-off of ?* from the tert-butyl to the neopentyl group and extrapolating from the experimental Taft plot.
- Koh, Han Joong,Lee, Hai Whang,Lee, Ikchoon
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p. 253 - 258
(2007/10/02)
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- A CONVENIENT SYNTHESIS OF UNSYMMETRICAL SECONDARY AMINES. IN SITU FORMATION OF UNSTABLE FORMALDEHYDE IMINES.
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The monoalkylation of aliphatic and aromatic primary amines can be accomplished by the reaction of organolithium or grignard reagents with N-(cyanomethyl) or N-(aminomethyl) derivatives.
- Overman, Larry E.,Burk, Robert M.
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p. 1635 - 1638
(2007/10/02)
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