Lanthanide borohydrides supported by an ansa-bis(amidinate) ligand with a rigid naphthalene linker: Synthesis, structure and catalytic activity in ring-opening polymerization of lactide

Mono- and bimetallic amidinate samarium complexes – synthesis, structure, and hydroamination catalysis

“…Trifonov, Shen and others employed bis(amidinates) linked by e.g. 1,3-diaminopropane, [32][33][34][35] o-, mand p-phenylene, [36][37][38][39][40] pyridinediyl, 39,40 1,4-cyclohexene, 36 naphthalene [41][42][43][44] or propyl 45 for the synthesis of mono-and bimetallic rare-earth complexes.…”

“…[46][47][48][49] Some of the bimetallic complexes ligated by linked bis(amidinates) have been employed as catalysts. 34,36,42,45 In general, bimetallic catalysts with both metals in well-defined distance to each other can feature cooperative substrate activation, a highly interesting property for the application in efficient catalytic transformations. [50][51][52][53] On the other hand, it is very challenging to obtain similar bimetallic catalysts together with their monometallic reference systems to study these effects in detail.…”

Catalytic Behavior of Rare-Earth Borohydride Complexes in Polymerization of Polar Monomers

“…Whereas atactic PLA was formed, the ROP of LLA afforded isotactic microstructures, as evaluated by analyses of the methine region of the decoupled 1 H NMR spectra (Kasperczyk, 1995). Finally, these same groups reported the ROP of rac-LA promoted by the moderately active heterobimetallic ansa-bis(amidinate) lanthanide borohydrides featuring a conformationally rigid naphthalene linker [1,8-C 10 H 6 {NC( t Bu)N-2,6-Me 2 -C 6 H 3 } 2 R (BH 4 ) 2 Li(THF) 2 ] (R¼ Nd Sm) (Yakovenko et al, 2012) (Table 2). However, the other chain-end group could not be unambiguously identified.…”

Magnesium and Zinc Complexes Supported by N,N,O Tridentate Ligands: Synthesis and Catalysis in the Ring‐Opening Polymerization of rac‐Lactide and α‐Methyltrimethylene Carbonate

“…A large number of metal complexes based predominantly (but not exclusively) on alkali metals, aluminum, iron,, titanium, zirconium,, magnesium, zinc, calcium, and trivalent lanthanides have been reported to be effective catalysts/initiators for the ROP of lactides. Among them, aluminum complexes, especially those supported by salen‐type ligands and their derivatives, exhibit satisfactory isoselectivities toward rac ‐lactide ( rac ‐LA) polymerization, which is highly desired for obtaining PLAs with enhanced thermal properties .…”