Dehydrative Cross-Coupling of 1-Phenylethanol Catalysed by Palladium Nanoparticles Formed in situ Under Acidic Conditions
Dehydrative Cross-Coupling of 1-Phenylethanol Catalysed by Palladium Nanoparticles Formed in situ Under Acidic Conditions
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DOI：
10.1055/s-0037-1610246
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发表时间：
2018-08
期刊：
影响因子：
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通讯作者：
J. Camp;Thomas W. Bousfield;Jay J. Dunsford;James Adams;J. Britton;M. Fay;A. Angelis-Dimakis
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文献类型：
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作者：
J. Camp;Thomas W. Bousfield;Jay J. Dunsford;James Adams;J. Britton;M. Fay;A. Angelis-Dimakis
摘要 在酸性条件下，实现了由糖衍生的原位形成的钯(0)纳米粒子催化的1-苯基乙醇的脱水交叉偶联。酸性条件允许在金属介导的偶联反应中使用醇作为原料，通过它们的原位脱水和随后的交叉偶联。对原位形成的钯纳米颗粒的尺寸和形态的广泛分析表明，零价金属被亲水性羟基包围。使用原型硅漂移探测器的 EDX-TEM 成像研究深入了解了分子氧在系统中的问题作用。对催化剂失活的理解的加深促进了交叉偶联方法的发展。与使用替代原料进行钯介导的二苯乙烯合成的相关两步方案相比，摩尔效率提高了 250-12,000 倍。这项工作开辟了一个新的研究领域，其中活性催化剂由可再生糖形成、稳定和再生。
Abstract A dehydrative cross-coupling of 1-phenylethanol catalysed by sugar derived, in situ formed palladium(0) nanoparticles under acidic conditions is realised. The acidic conditions allow for use of alcohols as a feedstock in metal-mediated coupling reactions via their in situ dehydration and subsequent cross-coupling. Extensive analysis of the size and morphology of the palladium nanoparticles formed in situ showed that the zero-valent metal was surrounded by hydrophilic hydroxyl groups. EDX-TEM imaging studies using a prototype silicon drift detector provided insight into the problematic role of molecular oxygen in the system. This increased understanding of the catalyst deactivation allowed for the development of the cross-coupling methodology. A 250-12,000 fold increase in molar efficiency was observed when compared to related two-step protocols that use alternative feedstocks for the palladium-mediated synthesis of stilbenes. This work opens up a new research area in which the active catalyst is formed, stabilised and regenerated by a renewable sugar.