The modification of heterogeneous catalysts through the chemisorption of chiral molecules is a method to create catalytic sites for enantioselective surface reactions. The chiral molecule is called a chiral modifier by analogy to the terms chiral auxiliary or chiral ligand used in homogeneous asymmetric catalysis. While there has been progress in understanding how chirality transfer occurs, the intrinsic difficulties in determining enantioselective reaction mechanisms are compounded by the multisite nature of heterogeneous catalysts and by the challenges facing stereospecific surface analysis. However, molecular descriptions have now emerged that are sufficiently detailed to herald rapid advances in the area. The driving force for the development of heterogeneous enantioselective catalysts stems, at the minimum, from the practical advantages they might offer over their homogeneous counterparts in terms of process scalability and catalyst reusability. The broader rewards from their study lie in the insights gained on factors controlling selectivity in heterogeneous catalysis. Reactions on surfaces to produce a desired enantiomer in high excess are particularly challenging since at room temperature, barrier differences as low as ∼2 kcal/mol between pathways to R and S products are sufficient to yield an enantiomeric ratio (er) of 90:10. Such small energy differences are comparable to weak interadsorbate interaction energies and are much smaller than chemisorption or even most physisorption energies.

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铂上单个非对映异构体配合物的结构和动力学：与非均相对映选择性催化有关的表面研究

通过手性分子的化学吸附改性多相催化剂是一种为对映选择性表面反应产生催化位点的方法。类似于在均相不对称催化中使用的术语手性助剂或手性配体，该手性分子被称为手性改性剂。尽管在理解手性转移是如何发生方面已有进展，但确定对映选择性反应机理的内在困难因非均相催化剂的多位性质和立体定向表面分析所面临的挑战而变得更加复杂。但是，现在已经出现了足够详细的分子描述，以预示该地区的快速发展。开发非均相对映选择性催化剂的驱动力至少要来自于 在工艺可扩展性和催化剂可重复使用性方面，它们比同类同类产品具有更多的实际优势。他们研究的广泛收获在于对控制多相催化选择性的因素的见解。表面上产生过量过量所需对映异构体的反应尤其具有挑战性，因为在室温下，通向反应的途径之间的势垒差低至约2 kcal / mol。R和S产物足以产生90:10的对映体比率（er）。如此小的能量差可与弱的被吸附物间相互作用能相媲美，并且比化学吸附能或什至大多数物理吸附能小得多。