Affiliation:
1. Department of Chemistry and Chemical Engineering Shandong University Jinan 250100 China
2. Mulliken Center for Theoretical Chemistry University of Bonn Beringstrasse 4 53115 Bonn Germany
Abstract
AbstractA nuclearity‐dependent enantiodivergent epoxide opening reaction has been developed, in which both antipodes of chiral alcohol products are selectively accessed by mononuclear (salen)TiIII complex and its self‐assembled oxygen‐bridged dinuclear counterparts within the same stereogenic ligand scaffold. Kinetic studies based on the Eyring equation revealed an enthalpy‐controlled enantio‐differentiation mode in mononuclear catalysis, whereas an entropy‐controlled one in dinuclear catalysis. DFT calculations outline the origin of the enantiocontrol of the mononuclear catalysis and indicate the actual catalyst species in the dinuclear catalytic system. The mechanistic insights may shed a light on a strategy for stereoswichable asymmetric catalysis utilizing nuclearity‐distinct transition‐metal complexes.
Funder
National Natural Science Foundation of China
Taishan Scholar Foundation of Shandong Province
Deutsche Forschungsgemeinschaft