Center for Time-Resolved Diffraction, Department of Chemistry, Graduate School of Nanoscience & Technology (WCU), KAIST, Daejeon, Korea.
J Am Chem Soc. 2010 Sep 1;132(34):12027-33. doi: 10.1021/ja104193s.
Herein we present the long-sought quantitative catalyst-substrate association relationships based on experimentally measured quantitative association preferences of diverse metathesis Mo and Ru catalysts (Mo-1, Schrock Mo; Mo-2, Schrock-Hoveyda Mo; Ru-1, Grubbs first generation Ru; Ru-2, Grubbs second generation Ru; Ru-3:, Grubbs-Hoveyda first generation Ru; and Ru-4, Grubbs-Hoveyda second generation Ru) to their substrates (alkenes, alkynes and allenes), determined directly by a general method based on FRET principle. The determined substrate preferences are proved to be dependent on the molecular identity of the catalyst, exhibiting the preference order of alkyne > alkene > allene for Mo-1 and Mo-2, allene > alkene > alkyne for Ru-1 and Ru-3, and alkyne > allene > alkene for Ru-2 and Ru-4. The results enable us to probe metathesis mechanisms by answering issues in metathesis reactions including the controversial reaction initiation in enyne or allenyne metathesis.
在此，我们根据基于 FRET 原理的通用方法直接测定了不同复分解 Mo 和 Ru 催化剂（Mo-1、Schrock Mo；Mo-2、Schrock-Hoveyda Mo；Ru-1、第一代 Grubbs Ru；Ru-2、第二代 Grubbs Ru；Ru-3：第一代 Grubbs-Hoveyda Ru；和 Ru-4、第二代 Grubbs-Hoveyda Ru）与其底物（烯烃、炔烃和丙二烯）之间长期以来寻求的定量催化剂-底物缔合关系，并证明了这些确定的底物偏好取决于催化剂的分子特性，对于 Mo-1 和 Mo-2，其表现出炔烃>烯烃>丙二烯的偏好顺序，对于 Ru-1 和 Ru-3，其表现出丙二烯>烯烃>炔烃的偏好顺序，而对于 Ru-2 和 Ru-4，则表现出炔烃>丙二烯>烯烃的偏好顺序。这些结果使我们能够通过回答复分解反应中的问题，包括烯炔或丙二烯复分解中存在争议的反应起始问题，来探究复分解机制。
