Cover Feature: Recent Advances in Rare‐Earth Metal‐Catalyzed C−H Functionalization Reactions (ChemCatChem 23/2022)

Abstract

The Cover Feature demonstrated all rare‐earth metal elements in the form of RE (abbreviation of rare‐earth) letters and a C−H bond was activated via rare‐earth metal catalysts and a C−R bond was consequently formed. In their Review, X. Xu and co‐workers provide a brief overview on rare‐earth metal‐catalyzed C−H functionalization reactions during the last decade. Transition metal catalyzed C−H functionalization has attracted great interest and witnessed considerable advances owing to its outstanding regioselectivity, step‐ and atom‐economy. In recent years, rare‐earth metal catalysts have exhibited unique reactivity and selectivity in C−H functionalization, making it an important complement for late‐transition metal‐catalyzed C−H functionalization. More information can be found in the Review by X. Xu and co‐workers.

Regioselective C–H alkylation of anisoles with olefins by cationic imidazolin-2-iminato scandium(iii) alkyl complexes

“…Rare-earth organic complexes have been emerging as competent catalysts for several important organic transformations, 7 including C–H functionalisation 8 and polymerisation reactions. 9 The development of this area, in particular C–H functionalisation, heavily relies on the use of cyclopentadienyl (Cp) and its analogues as ancillary ligands.…”

“… 15 Nevertheless, it remains unclear whether imidazolin-2-iminato rare-earth alkyl complexes could be used in C–H activation. Motivated by the distinct selectivity and functional group tolerance frequently shown in rare-earth mediated C–H functionalisation 8 and elegant work 11 from Tamm's group, we envisaged that the judicious choice of rare-earth ions and basic ligands, as well as modification of imidazolin-2-iminato supporting ligands, may have the potential to achieve C–H alkylation with olefins. Herein, we wish to disclose our preliminary results along this line.…”