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 wellknown frustrated Lewis pair (FLP) PtBu3/B(C6F5)(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.