Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States.
J Am Chem Soc. 2011 Mar 16;133(10):3332-5. doi: 10.1021/ja200311n. Epub 2011 Feb 22.
A catalytic method for enantioselective synthesis of homoallylamides through Cu-catalyzed reactions of stable and easily accessible (pinacolato)allylborons with aryl-, heteroaryl-, alkyl-, or alkenyl-substituted N-phosphinoylimines is disclosed. Transformations are promoted by 1-5 mol % of readily accessible NHC-Cu complexes, derived from C(1)-symmetric imidazolinium salts, which can be prepared in multigram quantities in four steps from commercially available materials. Allyl additions deliver the desired products in up to quantitative yield and 98.5:1.5 enantiomeric ratio and are amenable to gram-scale operations. A mechanistic model accounting for the observed selectivity levels and trends is proposed.
一种通过 Cu 催化稳定且易于获得的(频哪醇基)烯丙基硼与取代的芳基、杂芳基、烷基或烯基取代的 N-膦酰亚胺的反应对映选择性合成高烯丙基酰胺的催化方法。转化由易于获得的 NHC-Cu 配合物促进,该配合物由 C(1)-对称咪唑啉盐衍生而来,可从商业上可获得的材料通过四步反应以多克量制备。烯丙基加成以高达定量产率和 98.5:1.5 的对映体比例提供所需产物,并且适用于克级操作。提出了一个能够解释观察到的选择性水平和趋势的机理模型。