- Acid-catalyzed chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines
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Chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines were described, which were established on the basis of either a C[sbnd]C bond cleavage or a rearrangement process of a reaction intermediate. These reactions proceeded in a condition-determined manner with good functional group tolerance. In the first model, 2,2-dimethoxyacetaldehyde reacted with aniline to form a new C[sbnd]N bond, in the presence of O2, via a C[sbnd]C bond cleavage reaction. However, in the second model, by performing the reaction in the absence of O2, Heyns rearrangement occurred and generated a new C[sbnd]O bond to form methyl phenylglycinate. Such condition-determined reactions not only offered the new way for value-added conversion of biomass-derived platform molecule, 2, 2-dimethoxyacetaldehyde, but also provided efficient methods for the synthesis of N-arylformamides and methyl phenylglycinates.
- Guo, Luxia,Chen, Zihao,Zhu, Hongmei,Li, Minghao,Gu, Yanlong
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supporting information
p. 1419 - 1422
(2020/11/12)
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- Sulfated polyborate-catalyzed N-formylation of amines: a rapid, green and efficient protocol
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Abstract: A rapid, green and efficient method for N-formylation reaction of various amines with formic acid in the presence of sulfated polyborate catalyst under solvent-free conditions has been described. The catalyst has the advantage of mild Bronsted as well as Lewis acid character. The catalyst is recyclable with no significant loss in catalytic activity. The present protocol is advantageous due to its solvent-free condition, short reaction time, high yields, easy workup and ability to tolerate a variety of functional groups.
- Khatri, Chetan K.,Chaturbhuj, Ganesh U.
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p. 2513 - 2519
(2017/11/06)
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- Silver-Catalyzed Chemoselective [4+2] Annulation of Two Isocyanides: A General Route to Pyridone-Fused Carbo- and Heterocycles
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A silver-catalyzed chemoselective [4+2] annulation of aryl and heteroaryl isocyanides with α-substituted isocyanoacetamides was developed for the facile and efficient synthesis of 2-aminoquinolones, naphthyridines, and phenanthrolines. A mechanism for this multistep domino reaction is proposed on the basis of a13C-labeling experiment, according to which an unprecedented chemoselective heterodimerization of two different isocyanides generates an α-amidoketenimine intermediate, which undergoes 1,3-amino migration to form an α-imidoylketene, followed by 6 π electrocyclization.
- Hu, Zhongyan,Dong, Jinhuan,Men, Yang,Lin, Zhichen,Cai, Jinxiong,Xu, Xianxiu
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supporting information
p. 1805 - 1809
(2017/02/05)
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- Structural elucidation of thermolysis products of methyl N-methyl-N-nitrosoanthranilate
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Although it is common knowledge that N-nitroso compounds are thermally (and otherwise chemically) labile, little or nothing is known about the specific reactions that occur during thermal treatment of a compound possessing this functionality. Methyl N-met
- Miltojevi?, Ana B.,Radulovi?, Niko S.
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p. 53569 - 53585
(2015/06/30)
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- An eco-benign and highly efficient procedure for N-acylation catalyzed by heteropolyanion-based ionic liquids using carboxylic acid under solvent-free conditions
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An eco-benign and highly efficient route for N-acylation of amines has been developed by treating amines with corresponding carboxylic acids in the presence of 2 mol % of heteropolyanion-based ionic liquids as catalysts under solvent-free conditions. This practical reaction could tolerate a wide range of substrates. Thus, various N-acylation products including N-acyl α-amino acid derivatives were obtained in moderate to excellent yields at 70 C to 120 C. Moreover, recycling studies revealed that heteropolyanion-based ionic liquids were easily reusable for this N-acylation. This method provides a green and much improved protocol over the existing methods.
- Chen, Zhikai,Fu, Renzhong,Chai, Wen,Zheng, Hao,Sun, Lin,Lu, Qiang,Yuan, Rongxin
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p. 2237 - 2245
(2014/03/21)
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- The multicomponent approach to N-methyl peptides: Total synthesis of antibacterial (-)-viridic acid and analogues
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Two syntheses of natural viridic acid, an unusual triply N-methylated peptide with two anthranilate units, are presented. The first one is based on peptide-coupling strategies and affords the optically active natural product in 20% overall yield over six steps. A more economical approach with only four steps leads to the similarly active racemate by utilizing a Ugi four-component reaction (Ugi-4CR) as the key transformation. A small library of viridic acid analogues is readily available to provide first SAR insight. The biological activities of the natural product and its derivatives against the Gram-negative bacterium Aliivibrio fischeri were evaluated.
- Neves Filho, Ricardo A. W.,Stark, Sebastian,Westermann, Bernhard,Wessjohann, Ludger A.
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supporting information
p. 2085 - 2090
(2013/02/22)
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- N-Formylsaccharin: A new formylating agent
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N-Formylsaccharin, a very cheap reagent, has been revealed to be an efficient and chemoselective formylating agent of amines. Georg Thieme Verlag Stuttgart New York.
- Cochet, Thomas,Bellosta, Véronique,Greiner, Alfred,Roche, Didier,Cossy, Janine
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experimental part
p. 1920 - 1922
(2011/10/02)
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- Synthesis of 4-hydroxy-3-quinolinecarboxylic acid derivatives by a condensation/cyclization sequence between o-isocyanobenzoates and magnesium enolates
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Addition of magnesium ester and amide enolates, generated using an excess amount of a magnesium amide (from diisopropylamine and ethylmagnesium bromide), to o-isocyanobenzoates affords 4-hydroxy-3-quinolinecarboxylic esters and amides by a tandem Claisen-type condensation/cyclization sequence.
- Kobayashi, Kazuhiro,Nakashima, Toshio,Mano, Masaaki,Morikawa, Osamu,Konishi, Hisatoshi
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p. 602 - 603
(2007/10/03)
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