Synthesis of <i>N</i>-alkoxycarbonyl Pyrroles from <i>O</i>-Substituted Carbamates: A Synthetically Enabling Pyrrole Protection Strategy
作者:Jodie L. Hann、Catherine L. Lyall、Gabriele Kociok-Köhn、Simon E. Lewis
DOI:10.1021/acs.joc.3c01257
日期:2023.10.6
5-dimethoxytetrahydrofuran gives N-alkoxycarbonyl pyrroles in a single step and in good yield. By this method, several common amine protecting groups can be introduced on the pyrrole nitrogen. With the exception of N-Boc, N-alkoxycarbonyl groups have seen only minimal use for protection of the pyrrole nitrogen to date. Here, we show that N-alkoxycarbonyl protection can endow pyrrole with distinct reactivity in comparison
容易获得的O-取代氨基甲酸酯与2,5-二甲氧基四氢呋喃的缩合一步即可得到N-烷氧基羰基吡咯,收率良好。通过该方法,可以在吡咯氮上引入几种常见的胺保护基。迄今为止,除了N -Boc 之外,N-烷氧基羰基仅很少用于保护吡咯氮。在这里,我们表明,与N-磺酰基保护相比, N-烷氧基羰基保护可以赋予吡咯不同的反应性,例如,在使用羧酸和磺酸酐活化剂的吡咯酰化方案中。