Asymmetric catalysis of hetero-ene reactions with tridentate Schiff base chromium(III) complexes.
Asymmetric catalysis of hetero-ene reactions with tridentate Schiff base chromium(III) complexes.
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DOI：
10.1021/ja025588j
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发表时间：
2002-02
影响因子：
15
通讯作者：
Rebecca T. Ruck;E. Jacobsen
中科院分区：
文献类型：
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作者：
Rebecca T. Ruck;E. Jacobsen
三齿席夫碱铬(III)络合物1催化芳基醛与2-甲氧基丙烯或2-三甲基硅氧基丙烯之间的不对称杂烯反应，以高产率和对映选择性提供一系列β-羟基烯醇醚产物。对密切相关的铬配合物的 X 射线晶体分析揭示了桥联二聚结构，具有水合六配位 Cr(III) 中心。提出了一种机制，其中通过化学干燥剂（BaO或甲硅烷基烯醇醚）实现水解离，从而揭示醛络合的位点。
Tridentate Schiff base chromium(III) complex 1 catalyzes the asymmetric hetero-ene reaction between aryl aldehydes and either 2-methoxypropene or 2-trimethylsilyloxypropene to provide a series of beta-hydroxyenol ether products in high yields and enantioselectivities. X-ray crystallographic analysis of a closely related chromium complex reveals a bridged, dimeric structure bearing aquo-bound six-coordinate Cr(III) centers. A mechanism is proposed wherein water dissociation is effected by means of a chemical desiccant (BaO or silyl enol ether), thereby revealing the site for aldehyde complexation.