State Key Laboratory of Oganometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032, People's Republic of China.
J Am Chem Soc. 2014 Jan 8;136(1):405-11. doi: 10.1021/ja410707q. Epub 2013 Dec 24.
Exceptionally high activity (with a TON up to 4750) of the palladium complexes of SKP ligand was discovered in the catalysis of asymmetric allylic amination of MBH adducts with aromatic amines. A comprehensive mechanistic study indicates that the unique structural features of the SKP ligand, with a long P···P distance in its solid-state structure, were favorable for allowing two P atoms to play a bifunctional role in the catalysis. Herein, one of the P atom forms a C-P σ-bond with the terminal carbon atom of allyl moiety as a Lewis base, and an alternative P atom coordinates to Pd atom. The cooperative action of organo- and organometallic catalysis discovered in the present catalytic system is most likely responsible for its high activity, as well as excellent regio- and enantioselectivities. The mechanism disclosed in the present catalytic system is distinct from most of the currently recognized mechanisms for Pd-catalyzed allylic substitutions.
在 MBH 加合物与芳胺的不对称烯丙基胺化反应的催化中，发现 SKP 配体的钯配合物具有极高的活性（TON 高达 4750）。一项全面的机理研究表明，SKP 配体的独特结构特征，即在其固态结构中具有较长的 P···P 距离，有利于允许两个 P 原子在催化中发挥双功能作用。在此，一个 P 原子与烯丙基部分的末端碳原子形成 C-P σ 键，作为路易斯碱，另一个 P 原子与 Pd 原子配位。在本催化体系中发现的有机和有机金属催化的协同作用很可能是其高活性以及优异的区域和对映选择性的原因。本催化体系中揭示的机理与大多数目前公认的 Pd 催化烯丙基取代反应的机理不同。
