Electrophilic aromatic substitution with N-methoxy-N-acylnitrenium ions generated from N-chloro-N-methoxy amides: syntheses of nitrogen heterocyclic compounds bearing a N-methoxy amide group
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。
Intramolecular Cyclization with Nitrenium Ions Generated from<i>N</i>-Chloro-<i>N</i>-methoxyamides in Neutral Conditions
作者:Yasuo Kikugawa、Masahiro Shimada
DOI:10.1246/cl.1987.1771
日期:1987.9.5
Intramolecular aromatic substitution by a N-chloro-N-methoxyamide group to a suitably situated aromatic ring in the molecule is performed by using anhydrous zinc acetate and nitromethane as solvent to give nitrogen heterocycles in good yield.
Cyclization with Nitrenium Ions Generated from N-Methoxy- or N-Allyloxy-N-chloroamides with Anhydrous Zinc Acetate. Synthesys of N-Hydroxy- and N-Methoxynitrogen Heterocyclic Compounds
Electrophilic intramolecular aromatic substitution with an N-methoxy- or an N-allyloxy-acylnitrenium ion, generated by treatment of an N-methoxy- or an N-allyloxy-N-chloroamide with anhydrous zinc acetate in nitromethane, leads to formation of a nitrogen heterocyclic compound bearing an N-methoxy- or N-allyloxy group. The latter is readily converted to the corresponding N-hydroxy compound by palladium-catalyzed removal of the allyl group.
Kikugawa Yasuo, Shimada Masahiro, Matsumoto Kazuhiro, Heterocycles, 37 (1994) N 1, S 293-301