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环氧化合物还原成醇,是较为常见的反应。其区域选择性取决于所使用的还原剂。一般规律是:LiAlH_4类型的亲核性复合金属氢化物从空间障碍较小的部位接近氧,从而获得取代基较多的醇;而硼烷(尤其在BF_3存在之下)或铝烷类型的亲电性金属氢化物则使环氧化合物从相反方向开环并主要获得取代基较小的醇。锆氢试剂(Cp_2ZrHCl)对羰基化合物的还原已经详细研究,本文将研究环氧化合物的还原及其区域选择性,并进一步认识锆氢试剂在反应中的作用及其本质。
Reduction of epoxy compounds to alcohols is a more common reaction. Its area selectivity depends on the reducing agent used. The general rule is that the nucleophilic complex metal hydride of LiAlH 4 type is close to oxygen from the space where the steric hindrance is small, so as to obtain alcohol with more substituents; and boranes (especially in the presence of BF 3) Electrical metal hydrides then make the epoxy ring open in the opposite direction and predominantly give alcohols with lower substituents. Reduction of carbonyl compounds by zirconium hydride reagent (Cp_2ZrHCl) has been studied in detail. In this paper, the reduction of epoxy compounds and their regioselectivities will be investigated. The role and nature of zirconium hydride reagents in reaction will be further recognized.