Reductive Dehydrogenation of a Stannane via Multiple Sn−H Activation by Frustrated Lewis Pairs

A bulky substituted stannane Ar*SnH₃ (Ar*=2,6-(2',4',6'-triisopropylphenyl)phenyl) was treated with the well-known frustrated Lewis pair (FLP) PtBu₃ /B(C₆ F₅ )₃ in varying stoichiometries. To some degree, hydride abstraction and adduct formation is observed, leading to [Ar*SnH₂ (PtBu₃ )]⁺ which is rather unreactive toward further dehydrogenation. In a competing process, the FLP proved to be capable of completely striping-off hydrogen and hydrides to generate the first cationic phosphonio-stannylene [Ar*Sn(PtBu₃ )]⁺ . This behavior provides insight into the activation/abstraction mechanism processes involved in these Group 14 hydride derivatives.