Since the reaction is performed in ethanol, we also assessed whether solvolysis of PhSi(OiPr)H2 to PhSi(OEt)H2 occurs under the reaction conditions. First, we monitored a solution of 0.2 M PhSi(OiPr)H2 in EtOH by GC, which showed that formation of PhSi(OEt)H2 was already 91% complete within 2 min, and is fully complete within 17 min. We also found that the catalytic hydrogenation was more rapid in ethanol than isopropanol (see details in SI). This indicates that the solvolysis of the silane is rapid under catalytic conditions, which is consistent with a lack of significant induction period. Efforts to establish the rate law with the alkoxysilanes were unsuccessful (see SI), perhaps due to confounding kinetic contributions from solvolysis. We tentatively attribute the non-integer rate order for silane to silane decomposition via the known iron(II)catalyzed solvolysis to form inactive silyl products, such as PhSi(OEt)2H and PhSi(OEt)3. 8h, 17