- N-Alkenylation of hydroxamic acid derivatives with ethynyl benziodoxolone to synthesizecis-enamides through vinyl benziodoxolones
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The stereoselective synthesis ofcis-β-N-alkoxyamidevinyl benziodoxolones (cis-β-N-RO-amide-VBXs) fromO-alkyl hydroxamic acids in the presence of an ethynyl benziodoxolone-acetonitrile complex (EBX-MeCN) is reported herein. The reaction was performed under mild conditions including an aqueous solvent, a mild base, and room temperature. The reaction tolerated variousO-alkyl hydroxamic acids derived from carboxylic acids, such as amino acids, pharmaceuticals, and natural products. Vinyl dideuteratedcis-β-N-MeO-amide-VBXs were also synthesized using deuterium oxide as the deuterium source. Valine-derivedcis-β-N-MeO-amide-VBX was stereospecifically derivatized to hydroxamic acid-derivedcis-enamides without the loss of stereoselectivity or reduction in the deuterium/hydrogen ratio.
- Shimbo, Daisuke,Maruyama, Toshifumi,Tada, Norihiro,Itoh, Akichika
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supporting information
p. 2442 - 2447
(2021/04/02)
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- Organocatalytic Multicomponent Synthesis of α/β-Dipeptide Derivatives
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A straightforward multicomponent Knoevenagel-aza-Michael-cyclocondensation reaction involving readily available hydroxamic acid-derived from naturally occurring α-amino acids allows a diversity-oriented synthesis of novel isoxazolidin-5-ones possessing an N-protected α-amino acid pendant with good to high diastereoselectivities thanks to a match effect with a chiral organocatalyst. These diversely substituted heterocycles, easily isolated as a single diastereoisomer, proved to be versatile platforms for the formation of an array of α/β-dipeptide fragments.
- Martzel, Thomas,Annibaletto, Julien,Millet, Pierre,Pair, Etienne,Sanselme, Morgane,Oudeyer, Sylvain,Levacher, Vincent,Brière, Jean-Fran?ois
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supporting information
p. 8541 - 8545
(2020/06/24)
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- The synthesis of Nα-protected amino hydroxamic acids from Nα-protected amino acids employing versatile chlorinating agent CPI-Cl
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Racemization free synthesis of Nα-protected amino hydroxamic acids from Nα-protected amino acids employing the versatile chlorinating reagent CPI-Cl has been described in one-pot. The present protocol has shown compability towards urethane protecting groups like Boc, Cbz and Fmoc, and side chain protections of amino acids showed complete tolerance.
- Vathsala,Srinivasulu,Santhosh,Sureshbabu, Vommina V.
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p. 449 - 457
(2019/03/08)
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- An Environmentally Sustainable Mechanochemical Route to Hydroxamic Acid Derivatives
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An operationally simple, and cost efficient conversion of carboxylic acids into hydroxamic acid derivatives via a high-energy mechanochemical activation is presented. This ball milling methodology was applied to a wide variety of carboxylic acids dramatically improving purification issues associated with this class of molecules, which still remain one of the main bottlenecks of classical methodologies. (Figure presented.).
- Mocci, Rita,De Luca, Lidia,Delogu, Francesco,Porcheddu, Andrea
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supporting information
p. 3135 - 3144
(2016/10/09)
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- Ethyl 2-cyano-2-(4-nitrophenylsulfonyloxyimino)acetate-mediated lossen rearrangement: Single-pot racemization-free synthesis of hydroxamic acids and ureas from carboxylic acids
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Ethyl 2-cyano-2-(4-nitrophenylsulfonyloxyimino)acetate (4-NBsOXY) mediated Lossen rearrangement and its application for the synthesis of ureas is demonstrated. Required hydroxamic acids for the Lossen rearrangements were synthesized from carboxylic acids using the same reagent. Finally, reaction of an amine with the produced isocyanate resulted in urea. Good yields without racemization were achieved under milder and simpler reaction conditions. Reactions are compatible with common N-protecting groups, such as Boc, Fmoc, Cbz, and benzyl, as well as various OH protecting groups, such as tBu and Bzl. Conversion from carboxylic acid to urea is achieved in one pot. Most importantly, byproducts Oxyma [ethyl 2-cyano-2-(hydroxyimino)acetate] and 4-nitrobenzenesulfonic acid can be recovered easily and can be recycled to prepare the reagent. Thus, the method is environmentally friendly and cost-effective.
- Thalluri, Kishore,Manne, Srinivasa Rao,Dev, Dharm,Mandal, Bhubaneswar
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p. 3765 - 3775
(2014/05/20)
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- Solid phase synthesis of hydroxamic acids
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The solid phase synthesis of hydroxamic acids is presented. Carboxylic acid ester linked, polymer-supported CBZ-protected amino acids were displaced from the resin with aqueous hydroxylamine to provide the corresponding hydroxamic acids.
- Dankwardt, Sharon M.
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p. 761 - 761
(2007/10/03)
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