Polylactide (PLA) is a high potential bioplastic that can replace oil‐based plastics in a number of applications. To date, in spite of its known toxicity, a tin catalyst is used on industrial scale which should be replaced by a benign catalyst in the long run. Germanium is known to be unharmful while having similar properties as tin. Only few germylene catalysts are known so far and none has shown the potential for industrial application. We herein present Ge complexes in combination with zinc and copper, which show amazingly high polymerization activities for lactide in bulk at 150 °C. By systematical variation of the complex structure, proven by single‐crystal XRD and DFT calculations, structure–property relationships are found regarding the polymerization activity. Even in the presence of zinc and copper, germanium acts as the active site for polymerizing probably through the coordination–insertion mechanism to high molar mass polymers.

The reactions of monomeric C,N‐chelated organogermanium(II) hydride L(H)Ge⋅BH3 with organolithium salts RLi yielded lithium hydrogermanatoborates (Li(THF)2{BH3[L(H)GeR]})2. Compound (Li(THF)2{BH3[L(H)GePh]})2 was used as a source of LiH for the reduction of organic C=O or C=N bonds in nonpolar solvents accompanied by the elimination of a neutral complex L(Ph)Ge⋅BH3. The interaction of (Li(THF)2{BH3[L(H)GePh]})2 with the polar C=O bond was further investigated by computational studies revealing a plausible geometry of a pre‐reactive intermediate. The experimental and theoretical studies suggest that, although the Li atom of (Li(THF)2{BH3[L(H)GePh]})2 coordinates the C=O bond, the GeH fragment is the active species in the reduction reaction. Finally, benzaldehyde was reduced by a mixture of L(H)Ge⋅BH3 with PhLi in nonpolar solvents.

Set of [Ru(η6‐cymene)(R)XCl] (R=L1SnCl, L1GeCl L2PPh2, X=Cl or SnCl3, L1=[2‐(CH2NEt2)‐4,6‐(tBu)2C6H2]−, L2=2,6‐iPr2‐C6H3‐NH−) catalysts was tested in aerobic oxidations of primary amines. The activity of studied catalysts depends on the charge of the Ru atom that has been influenced either by donating ligands R or by character of X. Typical Ru/P catalyst [Ru(η6‐cymene)(L2PPh2)Cl2] (3) with least negative charge on the Ru atom has been observed as the most effective. The design of the phosphine ligand L2 containing amino‐phosphine PNH moiety provided efficient anchoring of complex 3 to silica gel via hydrogen bonding of the PNH functional group to SiO2 to give heterogeneous catalyst 3‐silica. This complex has been also efficiently tested in aerobic oxidation as recyclable catalyst with cumulative TON up to 6930.

The synthesis of the monomeric organogermanium(II) hydrides [(LGeH)M(CO)5] [M = Cr (4), W (5)] by utilizing the C,N‐chelating ligand L {L = [2‐(CH2NEt2)‐4,6‐tBu2C6H2]–} was explored. Stabilization of the GeH terminal bond in 4 and 5 was accompanied by a combination of electronic and steric protection of ligand L. The reactivity of the GeH terminal bond was also investigated, and attempts to reduce the polar C≡N bond in tBuNC provided an unexpected N–C bond‐cleavage reaction yielding organogermanium(II) cyanides [(LGeCN)M(CO)5] [M = Cr (6), W (7)] instead of a hydrogermylation reaction.

Monomeric organogermanium(II) hydrides {(LGeH)M-(CO) 5 } (M = Cr (1), W (2), L = [2-(CH 2 NEt 2 )-4,6-tBu 2 -C 6 H 2 ] -) were treated with ortho-quinones and terminal alkyne HC≡CCO 2 Me to give {[(LH)Ge(κ 2 -O 2 -3,5-tBu 2 C 6 H 2 )]M(CO) 5 } (M = Cr (3), W (4)), {[(LH)Ge(κ 2 -O 2 -3,4,5,6-Cl 4 C 6 )]M(CO) 5 } (M = Cr (5), W (6)) and {[LGeCH=CH(COOMe)]Cr(CO) 5 } (11). These reactions proceeded as catalyst-free reductions of C=O and C≡C bonds. Experimental data demonstrated zwitterionic character of Ge(II) complexes 3-6, where the 1,3,2-benzodioxagermylenolato anion involving the GeO 2 C 2 five membered ring coordinates the M(CO) 5 frag- [a]