本文报道了在乙炔基苯并恶唑啉酮-乙腈络合物(EBX-MeCN)存在下,由O-烷基异羟肟酸立体合成顺式-β- N-烷氧基酰胺乙烯基苯并恶唑烷(顺式-β - N -RO-酰胺-VBXs)。反应在温和的条件下进行,所述条件包括水性溶剂,温和的碱和室温。该反应容许各种衍生自羧酸的O-烷基异羟肟酸,例如氨基酸,药物和天然产物。还使用氧化氘作为氘源合成了乙烯基双氘化的顺式-β - N -MeO-酰胺-VBXs。缬氨酸衍生的顺式将-β - N - MeO-酰胺-VBX立体定向衍生为异羟肟酸衍生的顺式-酰胺,而不会失去立体选择性或降低氘/氢比。
The synthesis of Nα-protected amino hydroxamic acids from Nα-protected amino acids employing versatile chlorinating agent CPI-Cl
作者:U. Vathsala、C. Srinivasulu、L. Santhosh、Vommina V. Sureshbabu
DOI:10.24820/ark.5550190.p010.727
日期:——
Racemization free synthesis of N-protected aminohydroxamicacids from N-protected aminoacids 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 aminoacids showed complete tolerance.
Ethyl 2-Cyano-2-(4-nitrophenylsulfonyloxyimino)acetate-Mediated Lossen Rearrangement: Single-Pot Racemization-Free Synthesis of Hydroxamic Acids and Ureas from Carboxylic Acids
Ethyl 2-cyano-2-(4-nitrophenylsulfonyloxyimino)acetate (4-NBsOXY) mediated Lossenrearrangement and its application for the synthesis of ureas is demonstrated. Required hydroxamic acids for the Lossenrearrangements 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
multicomponent Knoevenagel‐aza‐Michael‐cyclocondensation reaction involving readily available hydroxamic acid‐derived from naturally occurring α‐aminoacids allows a diversity‐oriented synthesis of novel isoxazolidin‐5‐ones possessing an N‐protected α‐aminoacid pendant with good to high diastereoselectivities thanks to a match effect with a chiral organocatalyst. These diversely substituted heterocycles
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.