Synthesis of Rare-Earth-Metal Iminopyrrolyl Complexes from Alkyl Precursors: Ln→Al N-Ancillary Ligand Transfer

Abstract

Protonolysis of [YMe3] n with 2-{(N-2,6-dialkylphenyl)iminomethyl)}pyrroles (alkyl = iPr (L1), Me (L2)) gave homoleptic iminopyrrolyl complexes YL1 3 and YL2 3 as well as the complex [L2YL2,Me]2 containing a dianionic pyrrolaldiminato ligand, formed via methylation of the imino backbone. Treatment of the half-sandwich complex [(C5Me5)YMe2]3 and yttrocene (C5Me5)2YMe(THF) with either 2 or 1 equiv of HL afforded the monomeric complexes (C5Me5)YL2 and (C5Me5)2YL,respectively. The complex (C5Me5)YL2 2 readily underwent Ln→Al iminopyrrolyl ligand transfer in the presence of trimethylaluminum, producing the known (C5Me5)Y(AlMe4)2. Salt metatheses of homoleptic Ln(AlMe4)3 (Ln = Y, La) with KL gave complicated reaction mixtures from which the η5/η1:κ1 pyrrolaldiminato-bridged complex [L1,MeLa(AlMe4)]2 and bis(tetramethylaluminate) complex L2Y(AlMe4)2 could be isolated and crystallographically characterized. Moreover, the solid-state structures of YL2 3, [L2YL2,Me]2, (C5Me5)YL1 2, (C5Me5)2YL1, and L2AlMe2 are presented.

Hydrosilylation in Aryliminopyrrolide‐Substituted Silanes

“…However, the use of these ligands in main‐group chemistry is less developed. The most widely studied main‐group aryliminopyrrolide complexes are based on aluminum . In particular, these Al‐complexes find usage as catalysts in lactide ring‐opening polymerization (ROP) and guanylation .…”

Early Metal Di(pyridyl) Pyrrolide Complexes with Second Coordination Sphere Arene−π Interactions: Ligand Binding and Ethylene Polymerization

“…Such ancillary ligand transmetallation from Y to Al has been observed in a number of other systems including in related iminopyrrolide complexes. 37…”

Aluminates with Fluorinated Schiff Bases: Influence of the Alkali Metal–Fluorine Interactions in Structure Stabilization

“…Finally, to have clear evidence regarding the formation of [NaAlMe 4 ], the reaction between the alkali metal compound [NaL a ] with two equivalents of trimethylaluminium (AlMe 3 ) was performed (Scheme 4) [56]. In this reaction, the aluminium derivative [AlMe 2 (L a )] was clearly identified, which proves the possibility of ligand rearrangements in these systems.…”