Inducing Axial Chirality in a Supramolecular Catalyst.
Inducing Axial Chirality in a Supramolecular Catalyst.
复制标题
DOI：
10.1002/anie.201801048
复制
发表时间：
2018-04
影响因子：
--
通讯作者：
Katharina Marie Wenz;Günter Leonhardt‐Lutterbeck;B. Breit
中科院分区：
文献类型：
--
作者：
Katharina Marie Wenz;Günter Leonhardt‐Lutterbeck;B. Breit
利用密度泛函理论设计了一种新型的配体，它能够形成轴向手性的超分子配合物。两个手性单体，每个具有共价键合的手性助剂，形成一个双齿膦配体与扭曲，氢键键合的骨架后，协调过渡金属中心，这导致两个非对映异构体，tropos络合物。溶液中非对映异构体的比例非常依赖于温度和溶剂。铑和铂配合物通过NMR研究，ESI-MS测量，以及UV-VIS和圆二色光谱的组合进行了分析。在铑催化的α-脱氢氨基酸的不对称氢化反应中，手性自组织配体表现出良好的转化率和对映选择性。该研究为基于立体定向手性中心的超分子组装体的立体控制的新型配体设计开辟了道路。
A new type of ligand, which is able to form axially chiral, supramolecular complexes was designed using DFT calculations. Two chiral monomers, each featuring a covalently bound chiral auxiliary, form a bidentate phosphine ligand with a twisted, hydrogen-bonded backbone upon coordination to a transition metal center which results in two diastereomeric, tropos complexes. The ratio of the diastereomers in solution is very temperature- and solvent-dependent. Rhodium and platinum complexes were analyzed through a combination of NMR studies, ESI-MS measurements, as well as UV-VIS and circular dichroism spectroscopy. The chiral self-organized ligands were evaluated in the rhodium-catalyzed asymmetric hydrogenation of α-dehydrogenated amino acids and resulted in good conversion and high enantioselectivity. This research opens the way for new ligand designs based on stereocontrol of supramolecular assemblies through stereodirecting chiral centers.