Diverse Reactions of Formazanate/Formazan with Tetrylenes: Reduction, C−H Bond Activation, Substitution and Addition

The reactivity of the formazanate potassium salt [L$^{tBu}$K(thf)] (L$^{tBu=}$PhNNC(4-$^t$BuPh)NNPh) with the group 14 chlorotetrylenes [{PhC($^t$BuN)$_2$}ECl] (E=Si, Ge, Sn) was investigated. Three corresponding compounds with unique configurations were formed, demonstrating the diverse reactivity of the system. In addition to the anticipated salt metathesis reactions of the potassium salt with the chlorine function of tetrylenes, unexpected reduction/insertion steps into the N=N bond of the formazanate (Si, Ge) and subsequent C−H activation (Ge) were also observed. Furthermore, when the neutral formazan ligand [L$^{tBu}$H] was exposed to silylenes [{PhC($^t$BuN)$_2$}SiCl] and [L$^{Ph}$SiNMePy], substitution and addition reactions occurred. These discoveries significantly enrich the diversity of formazanate/formazan redox chemistry, opening up new avenues for exploration in this field.