Catalytic Kinetic Resolution of Disubstituted Piperidines by Enantioselective Acylation: Synthetic Utility and Mechanistic Insights
作者:Benedikt Wanner、Imants Kreituss、Osvaldo Gutierrez、Marisa C. Kozlowski、Jeffrey W. Bode
DOI:10.1021/jacs.5b07201
日期:2015.9.9
The catalytic kinetic resolution of cyclic amines with achiral N-heterocyclic carbenes and chiral hydroxamic acids has emerged as a promising method to obtain enantio-enriched amines with high selectivity factors. In this report, we describe the catalytic kinetic resolution of disubstituted piperdines with practical selectivity factors (s, up to 52) in which we uncovered an unexpected and pronounced
用非手性N-杂环卡宾和手性异羟肟酸催化动力学拆分环胺已成为一种有前途的方法,以高选择性因子获得对映体富集的胺。在本报告中,我们描述了具有实际选择性因子(s,高达 52)的二取代哌啶的催化动力学拆分,其中我们发现了意想不到的显着构象效应,导致顺式和反式取代的哌啶异构体之间存在不同的反应性和选择性。对各种二取代哌啶的动力学拆分的详细实验和计算研究揭示了对α-取代基占据轴向位置的构象异构体的酰化的强烈偏好。这项工作为酰基转移试剂的协调七元过渡态模型提供了进一步的实验和计算支持,并扩大了仲胺动力学拆分的范围和官能团耐受性。