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NaBH_4是一种高选择性和异常温和的亲核还原试剂。在一般情况下,它只能还原醛、酮和酰氯,而对其他宫能团不起作用。因而它的应用范围在某种程度上受到了限制。但NaBH_4价廉,易于处理,使用方便,故已成为有机合成用的重要试剂,受到了有机化学家的普遍重视。为了进一步扩大这一试剂的应用范围,许多化学家一直在致力于其还原性能的改善。研究结果表明,影响NaBH_4还原性能的因素主要有:反应温度、反应体系的pH值、溶剂、其他金属离子的作用、催化剂的作用、NaBH_4在介质中的分散程度以及底物分子中活性基团的影响。综合这些因素,已发展了许多提高NaBH_4还原能力的方法。
NaBH 4 is a highly selective and exceptionally mild nucleophilic reduction reagent. Under normal circumstances, it can only reduce aldehydes, ketones and acid chlorides, but not for other uterus. Thus its scope of application is somewhat limited. However, NaBH_4 is cheap, easy to handle and easy to use. Therefore, NaBH_4 has become an important reagent for organic synthesis and has received universal attention by organic chemists. To further expand the range of applications for this reagent, many chemists have been working to improve their reduction performance. The results show that the main factors affecting the reduction of NaBH_4 are: reaction temperature, pH value of the reaction system, the role of the solvent, other metal ions, the role of the catalyst, the degree of dispersion of NaBH_4 in the medium and the number of active groups influences. In combination with these factors, many methods have been developed to enhance the reducing ability of NaBH4.