Intramolecular rearrangement of α-amino acid amide derivatives of 2-aminobenzothiazoles
作者:Jeffrey C. Pelletier、Venkata Velvadapu、Mark E. McDonnell、Jay E. Wrobel、Allen B. Reitz
DOI:10.1016/j.tetlet.2014.05.046
日期:2014.7
conformational bias to further promote the intramolecular reaction such as for the 2-aminobenzothiazole amides derived from proline or 4-aminopiperidine-4-carboxylic acid. This rearrangement has not been described previously for α-amino acid amide derivatives of 2-aminobenzothiazoles. However, a related reaction involving 2-semicarbazido benzothiazoles has been recently reported.
我们发现 2-氨基苯并噻唑的 α-氨基酸酰胺衍生物会发生时间依赖性的热重排,其中氨基攻击噻唑环的 2 位碳以形成 5,5-螺环系统。随后硫离开和空气氧化成相应的对称二硫化物。如果存在构象偏差以进一步促进分子内反应,例如衍生自脯氨酸或 4-氨基哌啶-4-羧酸的 2-氨基苯并噻唑酰胺,则此类产品的分离产率非常高 (>70%)。这种重排以前没有描述过 2-氨基苯并噻唑的 α-氨基酸酰胺衍生物。然而,最近报道了涉及 2-氨基脲苯并噻唑的相关反应。