Synthesis of<i>C</i><sub>2</sub>-Symmetric Bisphosphine Ligands from Tartaric Acid, and Their Performance in the Pd-Catalyzed Asymmetric<i>O</i>-Allylation of a Phenol
作者:Mehmet Dindaroğlu、Sema Akyol Dinçer、Hans-Günther Schmalz
DOI:10.1002/ejoc.201402326
日期:2014.7
Starting from tartaric acid derived chiral diols or dicarboxylic acid dichlorides with either a 2,2-dimethyl-1,3-dioxolane (Taddol) or a 2,3-dimethoxy-2,3-dimethyl-1,4-dioxane (Tatrol) core structure, and BH3-protected ortho-phosphanyl phenols, a set of fourteen new C2-symmetric diphosphine ligands was synthesized. In addition, three related ligands were obtained from ortho-diphenylphosphino-anilines
从酒石酸衍生的手性二醇或二羧酸二氯化物与 2,2-二甲基-1,3-二氧戊环 (Taddol) 或 2,3-二甲氧基-2,3-二甲基-1,4-二氧六环 (Tatrol) 开始核心结构和 BH3 保护的邻膦酰基苯酚,合成了一组 14 个新的 C2 对称二膦配体。此外,三个相关的配体是从邻二苯基膦基苯胺中获得的。然后使用巴豆基甲基碳酸酯作为试剂在 Pd 催化的 4-甲氧基苯酚的对映选择性 O-烯丙基化反应中测试完全表征的配体。此外,还研究了使用碳酸巴豆基 4-甲氧基苯基酯作为底物的拟分子内反应变体。所谓的 Trost 配体被用作参考。尽管 Trost 配体 (3 mol-%) 的 ee 含量高达 84%,