- 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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supporting information
p. 6084 - 6093
(2019/05/24)
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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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- Aminomethylation reaction of Ortho -pyridyl C-H bonds catalyzed by group 3 metal triamido complexes
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Tris[N,N-bis(trimethylsilyl)amido] complexes of group 3 metals, especially yttrium and gadolinium, served as catalysts for ortho-C-H bond addition of pyridine derivatives and N-heteroaromatics into the C=N double bond of nonactivated imines to afford the corresponding aminomethylated products. Addition of catalytic amounts of secondary amines, such as dibenzylamine, dramatically improved the catalytic activity through the formation of a mixed ligated complex such as [(Me3Si)2N]2Y(NBn2)(THF) (4). Furthermore, kinetic studies using the isolated complex 4 provided a plausible reaction mechanism by which coordination of two pyridine derivatives afforded a penta-coordinated species as a key step.
- Nagae, Haruki,Shibata, Yu,Tsurugi, Hayato,Mashima, Kazushi
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supporting information
p. 640 - 643
(2015/01/30)
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- Iridium-catalyzed reduction of secondary amides to secondary amines and imines by diethylsilane
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Catalytic reduction of secondary amides to imines and secondary amines has been achieved using readily available iridium catalysts such as [Ir(COE) 2Cl]2 with diethylsilane as reductant. The stepwise reduction to secondary amine proceeds through an imine intermediate that can be isolated when only 2 equiv of silane is used. This system requires low catalyst loading and shows high efficiency (up to 1000 turnovers at room temperature with 99% conversion have been attained) and an appreciable level of functional group tolerance.
- Cheng, Chen,Brookhart, Maurice
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supporting information; experimental part
p. 11304 - 11307
(2012/09/05)
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- Convenient synthesis of angular triquinane from 4-alkenylfulvene via thermal cycloaddition followed by skeletal rearrangement of the resulting [4 + 2] adduct
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Alkenylfulvene prepared by the annulation of allylidenetriphenylphosphorane with 1,4-ynedione proceeded thermal cyclo-addition in a highly regio- and stereoselective manner to give [4 + 2] adduct which was then converted into triquinane derivative by the
- Inagaki, Sho,Imura, Keisuke,Morita, Toshio,Yoshimi, Yasuharu,Hatanaka, Minoru,Kawano, Tomikazu
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p. 454 - 455
(2008/09/20)
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- SYNTHESIS OF FUNCTIONALIZED 2,3-DIHYDRO-OXAZOLO-ISOINDOLINE-5-ONES
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The synthesis of 9b-functionalized 2,3-dihydro-oxazolo isoindoline-5-ones by reaction of 1-azaallylic carbanions with N-(2-bromoethyl)phtalimide is described.
- Kimpe, Norbert De,Yao, Zipeng,de Buyck, Laurent,Verhe, Roland,Schamp, Niceas
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p. 197 - 202
(2007/10/02)
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- Reactions of 1-Trichloromethyl-substituted Amines with Potassium tert-Butoxide
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The reaction of 1-trichloromethyl-substituted amines with tert-butoxide has been shown to provide important entries into a number of groups of functionalized amines, i.e., 2,2-dichlorovinylamines (which are also convertible into chloroynamines with a large excess of tert-butoxide), 2,2-dichloroenamines, N-(α-dichloromethylbenzylidene)amines and 2,2-dichloroaziridines.The formation of the products in individual cases depends upon the structure of the amine substrate.Keywords - 1-trichloromethyl-substituted amines; potassium tert-butoxide; 2-chloroynamines; 2,2-dichloroenamines; N-(α-dichloromethylbenzylidene)amines; 2,2-dichloroaziridines; elimination of hydrogen chloride
- Takamatsu, Masanori,Sekiya, Minoru
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p. 3098 - 3105
(2007/10/02)
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- Mono- and dialkylated prostynoic acid derivatives
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Novel mono- and dialkylated prostynoic acid derivatives, prepared by condensation of a suitably substituted cyclopentene carboxylic acid or ester with a suitable organometallic alkynyl derivative, display valuable pharmacological properties. For example, they are potent inhibitors of gastric secretion.
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