Metal-ammonia reduction. Effect of methyl substituents and a question concerning protonation sites in dianions
Metal-ammonia reduction. Effect of methyl substituents and a question concerning protonation sites in dianions
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金属-氨还原。
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
D. L. Huser
中科院分区：
文献类型：
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作者：
P. W. Rabideau;N. Peters;D. L. Huser
取代基对Birch还原和其他金属氨过程的影响受到了相当大的关注。由于中间体是带负电荷的，活化和取向效应已经在电子捐赠或取代基撤回方面进行了处理。甲基在萘和联苯中表现出一些不规则的行为，并在中间体中带电荷或不带电荷的碳上的甲基位置方面提供了解释。还观察到，质子化的二价阴离子（产生的电子加成）似乎总是导致最稳定的一价阴离子。对此原因进行了讨论。
The effect of substituents on Birch reductions and other metal-ammonia processes has received considerable attention. Since the intermediate(s) is negatively charged, activation and orientation effects have been dealt with in terms of electron donation or withdrawal of substituents. The methyl group displays somewhat irregular behavior in naphthalenes and biphenyls, and an explanation is offered in terms of methyl location on a charge-bearing or non-charge-bearing carbon in the intermediates. The observation is also made that protonation of dianions (produced by electron addition) always seems to lead to the most stable monoanion. Reasons for this are discussed.