Organometallic Rare Earths in Zeolites Are Activated for Hydrocarbon Functionalization

C-H borylation catalyzed by La in HY30 faujasite
C-H borylation catalyzed by La in HY30 faujasite.

Scientific Achievement

Labile coordination of organolanthanides, unlike transition-metal complexes, allows Ln(BH4)3THF3 to enter and graft in zeolite micropores, leading to confinement- and AlMe3-enabled unique activity for catalytic C-H borylation of hydrocarbons. 

Significance and Impact

Rare earth cations, traditionally used as structural stabilizers in petrochemical cracking catalysis, have been activated as organometallic sites for arene CH functionalization, establishing a foundation for commodity-scale conversions that conventionally require precious noble transition-metals.

Research Details

  • La(BH4)2AlMe3-SiPh3@HY30 catalyzes benzene borylation with >285 turnovers, nearly double that of its precursor.
  • La(BH4)2AlMe3@SiO2 is active for benzene borylation, unlike its catalytically inert precursor La(BH4)2(THF)2@SiO2.
  • Solid-state 11B NMR chemical shifts shows more charge-transfer from BH4 to La in ≡Si(≡AlO)-La(BH4)2AlMe3 than ≡SiOLa(BH4)2(THF)2, providing a rationale for the catalytic activity.

Li, Y.; Kobayashi, T.; Meira, D. M.; An, L.; Qi, L.; Sadow, A. D.. J. Am. Chem. Soc. 2025, 147, 12574-12586. https://doi.org/10.1021/jacs.4c18569