Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, China.
Chemistry. 2022 Nov 21;28(65):e202202528. doi: 10.1002/chem.202202528. Epub 2022 Sep 19.
Palladium-catalyzed enantioselective cyclization of enynes has contributed significantly to the construction of chiral cyclic molecules. In contrast, the catalytic asymmetric cyclization involving halopalladation remains an unresolved challenge with the inevitable disturbance of the halide ions. Herein, an intramolecular chlorine transfer strategy is used to accomplish the enantioselective chloropalladation cyclization of 1,6-enynes. This reaction provides a redox-neutral approach to a variety of chiral α-chloromethylene-γ-butyrolactones with excellent E selectivity and enantioselectivity. The precisely controlled coordination of palladium with both the in situ generated nucleophilic species and the monodentate phosphoramidite ligand is crucial for enantioselectivity.
钯催化的烯炔环化反应在构建手性环状分子方面做出了重要贡献。相比之下，涉及卤化钯化的催化不对称环化仍然是一个未解决的挑战，因为卤化物离子的存在不可避免地会造成干扰。在此，我们采用了分子内氯转移策略来实现 1,6-烯炔的对映选择性氯钯化环化反应。该反应为各种手性 α-氯亚甲基-γ-丁内酯提供了一种氧化还原中性的合成方法，具有优异的 E 选择性和对映选择性。钯与原位生成的亲核物种和单齿膦酰胺配体的精确配位对于对映选择性至关重要。
