Synthesis of Fe–H/Si–H and Fe–H/Ge–H Bifunctional Complexes and Their Catalytic Hydrogenation Reactions toward Nonpolar Unsaturated Organic Molecules

The iron hydride complexes bearing a Si–H or a Ge–H functional group in a ligand [2,5-SiPh3-3,4-butylene-(η5-C4COEEt2H)]­Fe­(CO)2H (E = Si (4), Ge (5)) and [2,5-SiPh3-3,4-butylene-(η5-C4COSiMe2OSiMe2H)]­Fe­(CO)2H (6), were synthesized in the reaction of the iron acetonitrile complex [2,5-SiPh3-3,4-butylene-(η4-C4CO)]­Fe­(CO)2(NCCH3) (3) with Et2EH2 or HSiMe2OSiMe2H. These complexes did not hydrogenate a polar unsaturated bond in either ketones or aldehydes but did hydrogenate a nonpolar unsaturated bond in alkynes and alkenes to give alkenes and alkanes selectively. These complexes also catalyzed a transfer hydrogenation reaction from isopropyl alcohol (IPA) to alkynes and alkenes.