Microwave-Assisted Protection of Primary Amines as 2,5-Dimethylpyrroles and Their Orthogonal Deprotection
作者:Amit Walia、Soosung Kang、Richard B Silverman
DOI:10.1021/jo401778e
日期:2013.11.1
Primary amines can be readily doubly protected as N-substituted 2,5-dimethylpyrroles. Although this protecting group is stable toward strong bases and nucleophiles, long reaction times are required for both the protection and deprotection steps, generally resulting in low deprotection yields. By employing microwave irradiation, protection and deprotection reaction times are dramatically reduced. Furthermore
伯胺可以很容易地被双重保护为N-取代的 2,5-二甲基吡咯。尽管该保护基团对强碱和亲核试剂稳定,但保护和脱保护步骤都需要较长的反应时间,通常导致脱保护产率低。通过使用微波辐射,保护和脱保护反应时间显着减少。此外,用乙醇中的稀盐酸脱保护可提高反应产率。结合微波辐射开发了多种脱保护条件,因此作为N-取代的 2,5-二甲基吡咯的保护可以与其他标准胺保护基团正交,例如叔-丁氧基羰基 (Boc)、苄氧基 (Cbz) 和 9-芴基甲氧基羰基 (Fmoc)。