Reduction of K⁺ or Li⁺ in the Heterobimetallic Electride K⁺[LiN(SiMe₃)₂]e^–

Abstract

Given their very negative redox potential (e.g., Li + → Li(0), −3.04 V; K + → K(0), −2.93 V), chemical reduction of Group-1 metal cations is one of the biggest challenges in inorganic chemistry: they are widely accepted as irreducible in the synthetic chemistry regime. Their reduction usually requires harsh electrochemical conditions. Herein we suggest a new strategy: via a heterobimetallic electride intermediate and using the nonbinding "free" electron as reductant. Based on our previously reported K + [LiN(SiMe 3 ) 2 ]e − heterobimetallic electride, we demonstrate the reducibility of both K + and Li + cations. Moreover, we find that external Lewis base ligands, namely tris[2-(dimethylamino)ethyl]amine (Me 6 Tren) or 2,2,2-cryptand, can exert a level of reducing selectivity by preferably binding to Li + (Me 6 Tren) or K + (2,2,2-cryptand), hence pushing the electron to the other cation.

Recent Advances in Dearomative Partial Reduction of Benzenoid Arenes

“…[3c,16] For example, Ito and Kubota [17] utilized Koide's synthetic strategy under mechanochemical conditions in which the transformation exhibits notable air-tolerance and high efficiency with only 1 min reaction time (Scheme 2a). Simultaneously, Lu and co-workers [18] reported an alternative Birch reduction of benzenes using a new sacrificial reductant, K + (LiHMDS)e À , under mechanochemical conditions (Scheme 2b).…”