Syntheses of high-valent open-chain metallostannylene hydride complexes from transition metal polyhydride complexes and aryl-substituted amidostannylenes are reported. The reaction of (MeBDIDipp)IrH4 (MeBDIDipp = (Dipp)NC(Me)CH(Me)CN(Dipp); Dipp = 2,6-diisopropylphenyl) with DMPSnN(SiMe3)2 (DMP = C6H3-2,6-Mes2, Mes = mesityl) gives access to metallostannylene (MeBDIDipp)IrH3SnDMP (1) with HN(SiMe3)2 as the byproduct. Similarly, treatment of Cp*IrH4 (Cp* = η5-C5Me5) with DMPSnN(SiMe3)2 leads to the formation of Cp*IrH3SnDMP (2). In contrast to 1, 2 cleanly reacts with a second equivalent of DMPSnN(SiMe3)2, allowing for the synthesis of bis(metallostannylene) Cp*IrH2(SnDMP)2 (3). Additionally, the synthesis and characterization of two new amidostannylenes DMPSn[N(Dipp)(SiMe3)] (4) and TripSn[N(Dipp)(SiMe3)] (5; Trip = 2,4,6-triisopropylphenyl) is presented. While the reaction of Cp*IrH4 with 4 represents an alternative route to 2, treatment of (MeBDIDipp)IrH4 with 5 yields the amidostannylene complex (MeBDIDipp)(H)2Ir═Sn(Trip){N(Dipp)(SiMe3)} (6) with concomitant release of H2, rendering stannylene coordination a reaction pathway that competes with Sn-N bond cleavage and metallostannylene formation. Within the broader context of transition metal-main group element compounds, metallostannylene formation is characterized as a formal deprotonation of the transition metal polyhydride complex by the amidostannylene. Notably, the ambiphilicity of amidostannylenes, which distinguishes them from tetravalent amidostannanes, appears to be essential for efficient Ir-Sn bond formation.