Rare-Earth-Metal Alkylaluminates Supported by N-Donor-Functionalized Cyclopentadienyl Ligands: CH Bond Activation and Performance in Isoprene Polymerization

Recent progress in rare-earth metal-catalyzed sp2 and sp3 C–H functionalization to construct C–C and C–heteroelement bonds

The review presents rare-earth metal-catalyzed C(sp2/sp3)–H functionalization accessing C–C/C–heteroatom bonds and olefin (co)polymerization, highlighting substrate scope, mechanistic realization, and origin of site-, enantio-/diastereo-selectivity.

Rare-earth metal-promoted (double) C–H-bond activation of a lutidinyl-functionalized alkoxy ligand: formation of [ONC] pincer-type ligands and implications for isoprene polymerization

Steric pressure enforces the formation of dianionic and trianionic pincer-type ligands involving a rare alkylidene moiety in the latter case.

Metal-directed self-assembly of transition metal heterometallascorpionates

3d metal-based heterometallascorpionates featuring high-spin Co(ii) and Ni(ii) centers were prepared and their structural, magnetic and electronic properties investigated.

Methyl Complexes of the Transition Metals

Organometallic chemistry can be considered as a wide area of knowledge that combines concepts of classic organic chemistry, that is, based essentially on carbon, with molecular inorganic chemistry, especially with coordination compounds. Transition-metal methyl complexes probably represent the simplest and most fundamental way to view how these two major areas of chemistry combine and merge into novel species with intriguing features in terms of reactivity, structure, and bonding. Citing more than 500 bibliographic references, this review aims to offer a concise view of recent advances in the field of transition-metal complexes containing M-CH3 fragments. Taking into account the impressive amount of data that are continuously provided by organometallic chemists in this area, this review is mainly focused on results of the last five years. After a panoramic overview on M-CH3 compounds of Groups 3 to 11, which includes the most recent landmark findings in this area, two further sections are dedicated to methyl-bridged complexes and reactivity.

Heterobi- and -trimetallic Ion Pairs of Zirconocene-Based Isoselective Olefin Polymerization Catalysts with AlMe₃

The reactivity towards AlMe3 of discrete cationic ansa-zirconocenes 2 a,b that are ubiquitously used in isoselective propylene polymerization and based on [{Ph(H)C(3,6-tBu2-Flu)(3-tBu-5-Et-Cp)}ZrMe2)] {Cp-Flu} and rac-[{Me2Si-(2-Me-4-Ph-Ind)2}ZrMe2] {SBI} was scrutinized. The first example of a structurally characterized Group 4 metallocene AlMe3 adduct (3 b) is reported. In the presence of excess AlMe3, the {SBI}-based AlMe3 adduct 3 b undergoes a slow decomposition via C-H activation in a bridging methyl unit to yield a new species (4 b) with a trimetallic {Zr(μ-CH2)(μ-Me)AlMe(μ-Me)AlMe2} core. EXSY NMR data for the process 2 b⇄3 b→4 b suggest very rapid and reversible binding of an additional AlMe3 molecule onto AlMe3 adduct 3 b. The resulting heterotrimetallic species intermediates exchange of methyl groups between different metal centers and slowly undergoes the C-H activation reaction towards 4 b.

Reactivity of halfsandwich rare-earth metal methylaluminates toward potassium (2,4,6-tri-tert-butylphenyl)amide and 1-adamantylamine

Donor functionalities drastically affect salt-metathetical methylaluminato–amido exchange reactions in Cp^RLn(AlMe₄)₂ by triggering methylaluminate cleavage and C–H bond activation of proximal aliphatic groups.