A mild deprotection method for notoriously difficult to unmask primary N-(p-toluenesulfonyl) amides was developed during our total synthesis studies toward the marine toxin, gymnodimine. The deprotection occurs at low temperature (-78 °C) under mild conditions by initial activation of the nitrogen with a trifluoroacetyl group, followed by reductive cleavage of the p-toluenesulfonyl group with samarium diiodide. The substrate scope and functional group tolerance of this useful N-S cleavage process, which builds on related cleavage processes of other nitrogen-heteroatom bonds, is explored.
在我们对海洋毒素裸二胺的全合成研究中,开发了一种温和的脱保护方法,用于众所周知难以揭露的初级 N-(对
甲苯磺酰)酰胺。脱保护发生在低温(-78°C)和温和条件下,首先用三
氟乙酰基活化氮,然后用二
碘化钐还原裂解对
甲苯磺酰基。探索了这种有用的 N-S 裂解过程的底物范围和官能团耐受性,该过程建立在其他氮-杂原子键的相关裂解过程的基础上。