- 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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- MANGANESE BASED COMPLEXES AND USES THEREOF FOR HOMOGENEOUS CATALYSIS
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The present invention relates to novel manganese complexes and their use, inter alia, for homogeneous catalysis in (1) the preparation of imine by dehydrogenative coupling of an alcohol and amine; (2) C-C coupling in Michael addition reaction using nitriles as Michael donors; (3) dehydrogenative coupling of alcohols to give esters and hydrogen gas (4) hydrogenation of esters to form alcohols (including hydrogenation of cyclic esters (lactones) or cyclic di-esters (di- lactones), or polyesters); (5) hydrogenation of amides (including cyclic dipeptides, lactams, diamide, polypeptides and polyamides) to alcohols and amines (or diamine); (6) hydrogenation of organic carbonates (including polycarbonates) to alcohols or hydrogenation of carbamates (including polycarbamates) or urea derivatives to alcohols and amines; (7) dehydrogenation of secondary alcohols to ketones; (8) amidation of esters (i.e., synthesis of amides from esters and amines); (9) acylation of alcohols using esters; (10) coupling of alcohols with water and a base to form carboxylic acids; and (11) preparation of amino acids or their salts by coupling of amino alcohols with water and a base. (12) preparation of amides (including formamides, cyclic dipeptides, diamide, lactams, polypeptides and polyamides) by dehydrogenative coupling of alcohols and amines; (13) preparation of imides from diols.
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Paragraph 00277-00278
(2017/09/05)
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- Manganese-Catalyzed Environmentally Benign Dehydrogenative Coupling of Alcohols and Amines to Form Aldimines and H2: A Catalytic and Mechanistic Study
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The catalytic dehydrogenative coupling of alcohols and amines to form aldimines represents an environmentally benign methodology in organic chemistry. This has been accomplished in recent years mainly with precious-metal-based catalysts. We present the dehydrogenative coupling of alcohols and amines to form imines and H2 that is catalyzed, for the first time, by a complex of the earth-abundant Mn. Detailed mechanistic study was carried out with the aid of NMR spectroscopy, intermediate isolation, and X-ray analysis.
- Mukherjee, Arup,Nerush, Alexander,Leitus, Gregory,Shimon, Linda J. W.,Ben David, Yehoshoa,Espinosa Jalapa, Noel Angel,Milstein, David
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supporting information
p. 4298 - 4301
(2016/05/09)
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- Palladium-catalyzed [4 + 2] cycloaddition of aldimines and 1,4-dipolar equivalents via amphiphilic allylation
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The combination of Pd catalyst and diethylzinc with triethylborane promotes the amphiphilic allylation of aldimines with 2,3-bismethylenebutane-1,4-diol derivatives to serve as bis-allylic zwitterion species to form 3,4-bismethylenepiperidines via a formal [4 + 2] cycloaddition reaction. 3,4-Bismethylenepiperidine rings are applicable for the synthesis of isoquinoline derivatives via the Diels-Alder reaction followed by an oxidation reaction with DDQ.
- Hirata, Goki,Yamada, Naoshi,Sanada, Shohei,Onodera, Gen,Kimura, Masanari
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supporting information
p. 600 - 603
(2015/03/04)
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- Discovery of substituted biphenyl imidazoles as potent, bioavailable bombesin receptor subtype-3 agonists
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We report SAR studies on a novel non-peptidic bombesin receptor subtype-3 (BRS-3) agonist lead series derived from high-throughput screening hit RY-337. This effort led to the discovery of compound 22e with significantly improved potency at both rodent and human BRS-3.
- He, Shuwen,Dobbelaar, Peter H.,Liu, Jian,Jian, Tianying,Sebhat, Iyassu K.,Lin, Linus S.,Goodman, Allan,Guo, Cheng,Guzzo, Peter R.,Hadden, Mark,Henderson, Alan J.,Ruenz, Megan,Sargent, Bruce J.,Yet, Larry,Kelly, Theresa M.,Palyha, Oksana,Kan, Yanqing,Pan, Jie,Chen, Howard,Marsh, Donald J.,Shearman, Lauren P.,Strack, Alison M.,Metzger, Joseph M.,Feighner, Scott D.,Tan, Carina,Howard, Andrew D.,Tamvakopoulos, Constantin,Peng, Qianping,Guan, Xiao-Ming,Reitman, Marc L.,Patchett, Arthur A.,Wyvratt Jr., Matthew J.,Nargund, Ravi P.
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scheme or table
p. 1913 - 1917
(2010/07/02)
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- Novel anti-tuberculosis agents from MCR libraries
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Structure-based design of libraries of multi-component reaction products yields novel potent anti-tuberculosis compounds. Synthesis and preliminary biological results are presented.
- Doemling, Alexander,Achatz, Sepp,Beck, Barbara
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p. 5483 - 5486
(2008/02/12)
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- New C-N and C-C bond forming reactions catalyzed by titanium complexes
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Titanium(iv) complexes with two basic dimethylamido ligands can be efficient catalysts for alkyne hydroamination by primary amines. Readily prepared pyrrolyl ligands have proven to be especially useful in generating active catalysts for hydroamination and
- Odom, Aaron L.
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p. 225 - 233
(2007/10/03)
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- Photoassisted C-H Bond Activation with RhCl(CO)(PR3)2 in the Presence of Isocyanides Leading to Catalytic formation of Aldimines
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C-H bond activation of benzene and pentane in the presence of isocyanides was promoted by RhCl(CO)(PR3)2 to result in the isocyanides insertion into C-H bonds.
- Tanaka, Masato,Sakakura, Toshiyasu,Tokunaga, Yuko,Sodeyama, Touru
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p. 2373 - 2374
(2007/10/02)
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