The selective hydrogenation of α,β-unsaturated aldehydes is a complex reaction. Of industrial interest is the thermodynamically unfavored hydrogenation of the carbonyl group, which is a prerequisite for the synthesis of pharmaceuticals and fragrances. Several strategies to enhance the selectivity using intermetallic compounds have been proposed, which are summarized and critically assessed concerning discrepancies between the reports in literature. Analysis shows that strategies enabling vertical adsorption of α,β-unsaturated aldehydes via the carbonyl group yield high selectivities to unsaturated alcohols. The frequently reported influence of charge transfer, which involves the presence of an intermetallic compound with high electronegativity difference of the constituent elements, does not correlate reliably with selectivity. Evaluation of the literature reveals that often a number of different influence factors might be responsible for enhanced selectivity, which are frequently hard to disentangle.

中文翻译：

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金属间化合物对 α，β-不饱和醛的选择性加氢 - 批判性综述


α，β-不饱和醛的选择性加氢是一个复杂的反应。工业上感兴趣的是热力学上不利的羰基加氢，这是合成药物和香料的先决条件。已经提出了几种使用金属间化合物提高选择性的策略，这些策略针对文献报告之间的差异进行了总结和批判性评估。分析表明，能够通过羰基垂直吸附 α，β-不饱和醛的策略对不饱和醇具有高选择性。经常报道的电荷转移影响，涉及组成元素具有高电负性差异的金属间化合物的存在，与选择性没有可靠的相关性。对文献的评估表明，通常许多不同的影响因素可能是导致选择性增强的原因，而这些因素通常很难理清。