Reduction of 1-arylpyrroles by metal-ammonia solutions
Reduction of 1-arylpyrroles by metal-ammonia solutions
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金属氨溶液还原 1-芳基吡咯
DOI：
10.1071/ch9691321
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发表时间：
1969
影响因子：
1.1
通讯作者：
K. Stapleford
中科院分区：
文献类型：
--
作者：
A. Birch;R. Rickards;K. Stapleford
在苯环的金属-氨还原中，发现最终添加的氢是2，5至排斥电子的取代基和1，4至电荷稳定的羧基，后者是主导作用。因此，在某些情况下可以使用羧基来迫使氢加成到烷基所占据的位置上，但该方法在某些情况下由于副反应而具有缺点。[1]另一个电子稳定基团是芳香环，它的作用可以用二苯基衍生物清楚地证明。2如果1-芳基吡咯（I）表现出类似的行为，则还原可能导致氢与苯环（11）的1，4-加成，因为吡咯本身是不可还原的，3并且由于吡咯基阴离子的稳定性，可能发生如（111）中的吡咯裂解。
In the metal-ammonia reduction of benzene rings, the hydrogens ultimately added are found 2, 5 to electron-repelling substituents and 1, 4 to the charge-stabilizing carboxyl group, the latter being a dominant effect. Carboxyl groups can therefore be used in some cases to force addition of hydrogen to positions occupied by alkyl groups, but the process has disadvantages in some cases because of side reactions. 1 Another electron-stabilizing group is an aromatic ring and its effect can clearly be demonstrated with diphenyl derivatives. 2 If 1-arylpyrroles (I) were to behave similarly, reduction could lead to 1, 4-addition of hydrogen to the benzenoid ring (11), since pyrroles themselves are not reducible, 3 and cleavage of the pyrrole as in (111) might then occur because of the stability of the pyrryl anion.