ASYMMETRIC MEMORY AT HETEROATOMS

合成光学纯硼配合物、氨基酸、 提出了酰胺、酯类化合物的合成方法。该方法的关键新特性 依赖于手性“ATE”络合物中的硼立体化学的控制 晶格效应。从硼中得到的环状“ATE”络合物 试剂和手性双功能底物形成为 非对映异构体，但结晶可以完全转化为一个 结晶异构体。随后的化学变化将被执行 低于非对映异构体通过可逆“ATE”相互转化的温度 复杂的解离，并将利用“不对称记忆” 暂时产生立体效应的硼。将这一概念应用于 介绍了天然和非天然氨基酸的合成，包括 催化烯醇烷基化反应的方法。 提出了一种新的对映体控制的烯醇质子化方法。 Lewis酸诱导内质子返回。 最后，上述方法中的一些方法将在短路线上使用，以具体 手性异构体和不同寻常的手性硼催化剂。

Methods for synthesis of optically pure boron complexes, amino acids, amides, and esters are proposed. The critical new feature of the method depends on control of boron stereochemistry in a chiral "ate" complex by crystal lattice effects. The cyclic "ate" complex obtained from the boron reagent and a chiral difunctional substrate is formed as a mixture of diastereomers, but crystallization allows complete conversion into one crystalline isomer. Subsequent chemical transformations would be performed below the temperature for diastereomer interconversion via reversible "ate" complex dissociation, and would take advantage of the "asymmetric memory" of temporarily stereogenic boron. Applications of this concept to the synthesis of natural and unnatural amino acids are described, including methods for catalytic enolate alkylation. A new method for enantiocontrolled enolate protonation is proposed using Lewis acid induced internal proton return. Finally, some of the above methods will be used in short routes to specific chiral atropisomers and unusual chiral boron catalysts.