使用Ni或Fe催化剂成功地实现了S N 2-选择性格利雅(Grignard)与伯烯丙基二苯基磷酸酯的偶联。与之形成鲜明对比的是,催化量的CuCN·2LiCl促进了S N 2'-选择性偶联反应。在铜催化剂的存在下,立体化学均一的γ-二取代的烯丙基格氏试剂在较少取代的烯丙基末端(α-位)与烯丙基磷酸二苯酯选择性地反应,而不会失去双键的几何形状。
Diastereocontrol in Asymmetric Allyl–Allyl Cross-Coupling: Stereocontrolled Reaction of Prochiral Allylboronates with Prochiral Allyl Chlorides
作者:Laura A. Brozek、Michael J. Ardolino、James P. Morken
DOI:10.1021/ja2075967
日期:2011.10.26
Palladium-catalyzed allyl-ally cross-coupling was investigated with substituted prochiral allylic boronates. These reactions deliver products bearing adjacent stereocenters, and the issue of diastereocontrol is therefore paramount. Under appropriately modified conditions, this allyl allyl coupling strategy was found to apply to a range of substrates, generally occurring with high enantioselectivity (92:8 to >99:1 er) and good diastereoselection (4:1 to 14:1 dr).