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
摘要:
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.
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。