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-SiPh 3 -3,4-butylene-(η 5 -C 4 COEEt 2 H)]Fe(CO) 2 H (E = Si ( 4 ), Ge ( 5 )) and [2,5-SiPh 3 -3,4-butylene-(η 5 -C 4 COSiMe 2 OSiMe 2 H)]Fe(CO) 2 H ( 6 ), were synthesized in the reaction of the iron acetonitrile complex [2,5-SiPh 3 -3,4-butylene-(η 4 -C 4 CO)]Fe(CO) 2 (NCCH 3 ) ( 3 ) with Et 2 EH 2 or HSiMe 2 OSiMe 2 H. 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.