Different Reaction Modes Operating in ansa‐Half‐Sandwich Magnesium Catalysts

Abstract

Magnesium‐based catalysts are becoming popular for hydroelementation reactions specially using p‐block reagents. Based on the seminal report from Schäfer’s group (ChemCatChem 2022, 14, e202201007), our study demonstrates that the reaction mechanisms exhibit a far greater degree of complexity than originally presumed. Magnesium has a variety of coordination modes (and access to different hybridizations) which allows this electron‐deficient centre to modulate its catalytic power depending on the σ‐donor properties of the reagent. DFT calculations demonstrate several reaction channels closely operating in these versatile catalysts. In addition, variations in limiting energy barriers resulting from catalyst modifications were examined as a function of the Hammett constant, thereby predicting enhanced efficiency in reaction conversions.

Deoxygenation of heterocyclic N-oxides employing iodide and formic acid as a sustainable reductant

“…In a recent previous work, we demonstrated that the coordination modes of the Mg metal center vary based on the σ-donor capability of the Lewis base. 25 Consequently, FA acts as a ligand and magnesium can coordinate up to four units, through the carbonyl O atom, resulting in Mg–O–C angles of approximately 120°. Contrary to what one might expect, FA-ligands are monodentate and not bidentate.…”