Uncovering the Importance of Proton Donors in TmI₂‐Promoted Electron Transfer: Facile CN Bond Cleavage in Unactivated Amides

Abstract

Nichtklassische Lanthanoid(II)‐iodide sind moderne Reagentien für schwierige Elektronentransferprozesse. Es wird gezeigt, dass Alkohole Thuliumdiiodid als erstes nichtklassisches Lanthanoid(II)‐iodid in der Reihe TmI2‐DyI2‐NdI2 in ein thermodynamisch stärkeres Reduktionsmittel überführen können. Das Reagens TmI2(ROH)n bewirkt eine beispiellose C‐N‐σ‐Bindungsspaltung in Amiden.

Metal‐Free Reductive Cleavage of CN and SN Bonds by Photoactivated Electron Transfer from a Neutral Organic Donor

“…In the event, protection of the nitrogen atom as an acetamide (39 c), a pivalamide (39 d), and a urethane (39 e), all enhanced the cleavage of the allyl group. [13] A blank experiment was also conducted on 39 c (in the absence of photoactivation) and this .…”

“…The electron-withdrawing acyl group can lower the LUMO energy and hence make electron transfer to the LUMO easier. In the event, protection of the nitrogen atom as an acetamide ( 39 c ), a pivalamide ( 39 d ), and a urethane ( 39 e ), all enhanced the cleavage of the allyl group 13. A blank experiment was also conducted on 39 c (in the absence of photoactivation) and this showed no conversion into the product, but rather quantitative recovery of 39 c , thus illustrating the essential role of the photoactivation of the donor.…”

Two dimensional inorganic electride-promoted electron transfer efficiency in transfer hydrogenation of alkynes and alkenes

“…In this regard, many types of materials, such as simple metals (Mg and Yb), stabilized alkali metal systems (Na in silica-gel and in ammonia liquid), and lanthanide iodides (SmI 2 and TmI 2 ), have been employed in electron transfer hydrogenation. 7 Despite their effectiveness in the reported transfer hydrogenations, there are several drawbacks in the methodology. Major disadvantages include the toxicity, the cost of agents and the rigorous reaction conditions.…”

Catalyst‐Free Photoredox Addition–Cyclisations: Exploitation of Natural Synergy between Aryl Acetic Acids and Maleimide

“…Unfortunately, organotin‐hydride reagents are notoriously toxic12, 13 and their residues difficult to remove,14 thus precluding their use in the synthesis of pharmaceuticals, foodstuffs or other formulations intended for human consumption. Alternatives are now available, but to date the ‘tyranny of tin’ remains strong 14–19…”