Synthesis and X‐ray Structures of the Polycyclic Dimers {[PhB(μ‐NtBu)2AsN(tBu)H]LiI}2 and [PhB(μ‐NtBu)2AsN(tBu)Li]2

Abstract

AbstractThe metathesis of [PhB(μ‐NtBu)2]AsCl and tBuN(H)Li in 1:1 molar ratio in diethyl ether produced the amido derivative [PhB(μ‐NtBu)2AsN(tBu)H] (1) in good yield. The lithiation of 1 with one equivalent of nBuLi afforded the lithium salt [PhB(μ‐NtBu)2AsN(tBu)Li] (2a). Both 1 and 2a were characterized by multinuclear NMR spectroscopy. The crystal structure of 2a is comprised of a U‐shaped, centrosymmetric dimer in which the monomeric [PhB(μ‐NtBu)2AsN(tBu)]−Li+ units are linked by Li‐N interactions to give a six‐rung ladder. Oxidation of 2a with one‐half equivalent of I2 in diethyl ether resulted in hydrogen abstraction from the solvent to give the dimeric lithium iodide adduct {[PhB(μ‐NtBu)2AsN(tBu)H]LiI}2 (1·LiI) with a central Li2I2 ring.