Scandium and Lutetium Metallacyclopropanes: Synthesis, Bonding, and Sterically Driven Reactivity
Dajiang Huang1, Tianyu Li1, Miaomiao Zhu1
1Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, China.
None:
As the class of the smallest metallacycles, transition-metal metallacyclopropanes have been widely studied, whereas scandium, yttrium, and lanthanide analogues have remained elusive. Herein, we report the first synthesis and characterization of scandium and lutetium metallacyclopropanes, 2-Sc and 2-Lu. Reactivity studies reveal a striking divergence: while 2-Sc is limited to redox processes, 2-Lu displays versatile insertion reactivity with various unsaturated substrates. DFT analysis indicates that the superior reactivity of 2-Lu is not driven by electronic nucleophilicity but rather by kinetic accessibility. The larger ionic radius and rare coordination mode of the Lu center provide a more open coordination sphere that outweighs electronic stabilization. This work highlights the important role of steric accessibility in controlling the divergent reactivity of highly strained Sc- and Lu-metallacyclopropane complexes.
Related Concept Videos
Cycloaddition Reactions: MO Requirements for Thermal Activation
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Properties of Organometallic Compounds
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Predicting Molecular Geometry
Cycloaddition Reactions: MO Requirements for Photochemical Activation


