- Tf2O/TTBP (2,4,6-Tri-tert-butylpyrimidine): An Alternative Amide Activation System for the Direct Transformations of Both Tertiary and Secondary Amides
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Ten types of Tf2O/TTBP-mediated amide transformation reactions were investigated. The results showed that compared with pyridine derivatives 2,6-di-tert-butyl-4-methylpyridine (DTBMP) and 2-fluoropyridine (2-F-Pyr.), TTBP can serve as an alternative amide activation system for the direct transformation of both secondary and tertiary amides. For most surveyed examples, higher or comparable yields were generally obtained. In addition, Tf2O/TTBP combination was used to promote the condensation reactions of 2-(tert-butyldimethylsilyloxy)furan (TBSOF) with both tertiary and secondary amides, the one-pot reductive Bischler-Napieralski-type reaction of tertiary lactams, and Movassaghi and Hill's modern version of the Bischler-Napieralski reaction. The value of the Tf2O/TTBP-based methodology was further demonstrated by the concise and high-yielding syntheses of several natural products.
- He, Qian,Ye, Jian-Liang,Xu, Fang-Fang,Geng, Hui,Chen, Ting-Ting,Chen, Hang,Huang, Pei-Qiang
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- A general method for the direct transformation of common tertiary amides into ketones and amines by addition of Grignard reagents
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The direct transformation of amides into ketones by addition of organometallic reagents has attracted the attention of organic chemists for a long time. However limited methods are reliable for common amides and have found synthetic applications. Here we report a method featuring in situ activation of tertiary amides with triflic anhydride (Tf2O) followed by addition of Grignard reagents. The method displays a good generality in scope for both amides and Grignard reagents, and it can be viewed as the acylation of Grignard reagents using amides as stable and selective acylating agents. Moreover, this deaminative alkylation reaction provides a mild method for the N-Deacylation of amides to give free amines.
- Huang, Pei-Qiang,Wang, Yu,Xiao, Kai-Jiong,Huang, Ying-Hong
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p. 4248 - 4254
(2015/06/02)
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- A new vanadium(IV)-bridged polyoxotungstate containing mixed valence-antimony(III,V)
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A new mixed-valence SbV/III containing vanadium-substituted polyoxotungstate Na10[{SbV(OH)3} 2{VIV-O(H2O)}2{Sb IIIW9O33}2]·32H2O (1-Na) has been synthesized by routine synthetic reaction and characterized by IR, XPS, elemental analysis. The polyoxoanion [{SbV(OH)3}2{V IVO(H2O)}2{SbIIIW9O33}2]10 (1) consists of two trilacunary species β-B-SbIIIW9O 33 connected by two VIVO(H2O) groups and two SbV(OH)3 units. The cyclic voltammetry and catalytic activity of 1-Na for the oxidation of n-hexadecane under green condition have been measured.
- Wang, Bin,Xu, Ling-Xiao,Meng, Rui-Qi,Suo, Lin,Li, Bao,Wu, Li-Xin,Bi, Li-Hua
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p. 274 - 278
(2013/10/22)
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- Organoruthenium-supported polyoxotungstate - Synthesis, structure and oxidation of n-hexadecane with air
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A ruthenium complex, KNa[Ru2(C6H6) 2(CH3COO)6] (Ru-KNa), and its polyoxotungstate derivative, Na6[{Ru(C6H6)}2W 8O28(OH)2]·16H2O (Ru-Na), have been successfully isolated from routine synthetic reactions and characterized by X-ray single-crystal structure analysis, IR spectroscopy and elemental analysis. A remarkable aspect of Ru-KNa is that it has two ligand types, benzene and acetate, and the acetate ligands are connected exclusively by a central Na cation to form a dimeric sandwich-type structure, which is further connected by K cations to construct the 3D structures. Based on complex Ru-KNa, the compound Ru-Na was synthesized, and it consists of two {Ru(C 6H6)} units linked to a [W8O 28(OH)2]10- fragment by three Ru-O(W) bonds to result in an assembly with idealized C2 symmetry in which the polyanions form 3D structures by the connection of Na chains. Subsequently, the compound Ru-Na was anchored on (3-aminopropyl)triethoxysilane (apts) modified SBA-15 to prepare the solid catalysts, which were characterized by powder XRD, N2 adsorption measurements and FTIR spectroscopy. Finally, the catalytic efficiency of Ru-Na was assessed in the oxidation of n-hexadecane with air without any additives and solvents. The results indicated that Ru-Na is a heterogeneous catalyst and exhibits higher catalytic activity than previously reported Ru-containing polyoxotungstates. Copyright
- Meng, Rui-Qi,Wang, Bin,Sui, Hui-Min,Li, Bao,Song, Wei,Wu, Li-Xin,Zhao, Bing,Bi, Li-Hua
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p. 1935 - 1942
(2013/05/23)
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- Convenient Synthesis of Functionalized Dialkyl Ketones and Alkanoylsilanes: 1-(Benzotriazol-1-yl)-1-phenoxyalkanes as Alkanoyl Anion Equivalents
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(Benzotriazol-1-yl)-1-phenoxyalkanes 10, prepared by two-step transformations of the corresponding aldehydes, are readily deprotonated at the methine group by BuLi.Subsequent reactions with alkyl halides, aldehydes, ketones, and imines yield the corresponding substituted derivatives that undergo hydrolysis under acidic conditions to afford the expected functionalized ketones 13, 15, 17, 19, 21, 24 and 25.Two successive lithiations of (benzotriazolyl)phenoxymethane, each followed by reaction with a trialkylsilyl chloride, alkyl halide, aldehyde, or ketone, generate similar intermediates 27, 39, 31, 33, and 36.Subsequent hydrolyses of 27, 29, 31, 33, and 36 yield the functionalized ketones 28, 30, and 32 and the alkanoylsilanes 34 and 37 in good yields.
- Katritzky, Alan R.,Lang, Hengyuan,Wang, Zuoquan,Lie, Zhu
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p. 7551 - 7557
(2007/10/03)
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- DEFLUORINATIVE COUPLING REACTIONS OF gem-DIFLUOROOLEFINS WITH ORGANOLITHIUM REAGENTS. NOVEL, FACILE METHODS FOR CHAIN ELONGATIONS OF ALDEHYDES LEADING TO AMIDES, ACETYLENES, AND KETONES
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Three types of coupling reactions of gem-difluoroolefins derived easily from aldehydes with lithium reagents (R'Li and R'2NLi) are described which constitute the facile procedures for conversions of aldehydes (RCHO) to amides (RCH2CONR'2), acetylenes (RCCR'), and ketones (RCH2COR').
- Hayashi, Sei-ichi,Nakai, Takeshi,Ishikawa, Nobuo
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p. 935 - 938
(2007/10/02)
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- Cycloalkanones. 8. Hypocholesterolemic activity of long chain ketones related to pentadecanone
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Aliphatic analogs of 2,8 dibenzylcyclooctanone which included C15-C18 ketones have been investigated for hypocholesterolemic activity in rats. The position of the carbonyl group in the chain for maximum activity appears to be the 2 position. 2 Hexadecanone reduced serum cholesterol levels significantly without altering serum triglyceride levels. This drug was not estrogenic at effective doses which is in contrast to the cyclooctanones which possess this activity.
- Wyrick,Hall,Piantadosi,Fenske
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p. 219 - 222
(2007/10/12)
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