2015, Verkade, Jorge M. M., Quaedflieg, Peter J. L. M., Verzijl, Gerard K. M., Lefort, Laurent, van Delft, Floris L., de Vries, Johannes G., Rutjes, Floris P. J. T.

The γ-amino alcohol structural motif is often encountered in drugs and natural products. We developed two complementary catalytic diastereoselective methods for the synthesis of N-PMP-protected γ-amino alcohols from the corresponding ketones. The anti-products were obtained through Ir-catalyzed asymmetric transfer hydrogenation, the syn-products via Rh-catalyzed asymmetric hydrogenation.

2019, Ye, X., Cui, J., Li, B., Li, N., Wang, R., Yan, Z., Tan, J., Zhang, J., Wan, X.

Selective crystallization represents one of the most economical and convenient methods to provide large-scale optically pure chiral compounds. Although significant development has been achieved since Pasteur’s separation of sodium ammonium tartrate in 1848, this method is still fundamentally low efficient (low transformation ratio or high labor). Herein, we describe an enantiomer-selective-magnetization strategy for quantitatively separating the crystals of conglomerates by using a kind of magnetic nano-splitters. These nano-splitters would be selectively wrapped into the S-crystals, leading to the formation of the crystals with different physical properties from that of R-crystals. As a result of efficient separation under magnetic field, high purity chiral compounds (99.2 ee% for R-crystals, 95.0 ee% for S-crystals) can be obtained in a simple one-step crystallization process with a high separation yield (95.1%). Moreover, the nano-splitters show expandability and excellent recyclability. We foresee their great potential in developing chiral separation methods used on different scales. © 2019, The Author(s).

2019, Steinlechner, Christoph, Spannenberg, Anke, Junge, Henrik, Beller, Matthias

In the title compound, [Mo(C10H12N2O)(CO)4], the molybdenum(0) center is surrounded by a bidentate di­imine [4,4-dimethyl-2-(pyridin-2-yl)-2-oxazoline] and four carbonyl ligands in a distorted octa­hedral coordination geometry. The di­imine ligand coordinates via the two nitro­gen atoms.

2011, Outouch, R., Boualy, B., El Firdoussi, L., Ali, M.A., Rizzoli, C., Spannenberg, A.

C16H23NO2, orthorhombic, P2 12121 (no. 19), a = 5.9637(3) Å, b = 8.8317(5) Å, c = 27.809(1) Å, V = 1464.7 Å3, Z = 4, Rgt(F) = 0.026, wRref(F2) = 0.040, T= 150 K.

2015, Smith, Dan A., Beweries, Torsten, Blasius, Clemens, Jasim, Naseralla, Nazir, Ruqia, Nazir, Sadia, Robertson, Craig C., Whitwood, Adrian C., Hunter, Christopher A., Brammer, Lee, Perutz, Robin N.

The association constants and enthalpies for the binding of hydrogen bond donors to group 10 transition metal complexes featuring a single fluoride ligand (trans-[Ni(F)(2-C5NF4)(PR3)2], R = Et 1a, Cy 1b, trans-[Pd(F)(4-C5NF4)(PCy3)2] 2, trans-[Pt(F){2-C5NF2H(CF3)}(PCy3)2] 3 and of group 4 difluorides (Cp2MF2, M = Ti 4a, Zr 5a, Hf 6a; Cp*2MF2, M = Ti 4b, Zr 5b, Hf 6b) are reported. These measurements allow placement of these fluoride ligands on the scales of organic H-bond acceptor strength. The H-bond acceptor capability β (Hunter scale) for the group 10 metal fluorides is far greater (1a 12.1, 1b 9.7, 2 11.6, 3 11.0) than that for group 4 metal fluorides (4a 5.8, 5a 4.7, 6a 4.7, 4b 6.9, 5b 5.6, 6b 5.4), demonstrating that the group 10 fluorides are comparable to the strongest organic H-bond acceptors, such as Me3NO, whereas group 4 fluorides fall in the same range as N-bases aniline through pyridine. Additionally, the measurement of the binding enthalpy of 4-fluorophenol to 1a in carbon tetrachloride (−23.5 ± 0.3 kJ mol–1) interlocks our study with Laurence’s scale of H-bond basicity of organic molecules. The much greater polarity of group 10 metal fluorides than that of the group 4 metal fluorides is consistent with the importance of pπ–dπ bonding in the latter. The polarity of the group 10 metal fluorides indicates their potential as building blocks for hydrogen-bonded assemblies. The synthesis of trans-[Ni(F){2-C5NF3(NH2)}(PEt3)2], which exhibits an extended chain structure assembled by hydrogen bonds between the amine and metal-fluoride groups, confirms this hypothesis.

2018, Höhne, Martha, Gongoll, Marc, Spannenberg, Anke, Müller, Bernd H., Peulecke, Normen, Rosenthal, Uwe

The title complex, [Mo(C24H30N2P2)(CO)4], contains a molybdenum centre bearing a P,P′-cis-chelating Ph2PN(iPr)P(Ph)NH(iPr) and four carbonyl ligands in a distorted octa­hedral coordination geometry. This results in a nearly planar four-membered metallacycle. In the crystal, mol­ecules are linked by N—H...O and C—H...O hydrogen bonds to form layers parallel to the ac plane. For the final refinement, the contributions of disordered solvent mol­ecules were removed from the diffraction data with SQUEEZE in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The given chemical formula and other crystal data do not take into account the unknown solvent mol­ecule(s).

2018, Höhne, Martha, Aluri, Bhaskar, Spannenberg, Anke, Müller, Bernd H., Peulecke, Normen, Rosenthal, Uwe

The title compound, C24H22N2OP2, is an asymmetrically substituted hydrazine derivative bearing a phosphoryl and a phosphanyl substituent. The PNNP backbone has a torsion angle of −131.01 (8)°. In the crystal, mol­ecules form centrosymmetric dimers by inter­molecular N—H...O hydrogen bonds, which are further linked into a three-dimensional network by weak C—H...O and C—H...π inter­actions.

2018, Höhne, Martha, Spannenberg, Anke, Müller, Bernd H., Peulecke, Normen, Rosenthal, Uwe

The title complex, [LiMo(C6H16N2)(C24H29N2P2)(CO)4], contains a distorted octa­hedrally coordinated molybdenum centre bearing a li­thia­ted P,P′-cis-chelating PNPN ligand, which results in a nearly planar four-membered metallacycle. The Li atom is coordinated by one equivalent tetra­methyl­ethylenedi­amine. In the crystal, mol­ecules are linked via weak C—H...O inter­actions, forming a chain along the b-axis direction.

2018, Peppel, Tim, Spannenberg, Anke

The title compound, (C9H14N4)[CoBr4], was obtained as single crystals directly in very low yield as a side product in the reaction of 1,1′-bis­(1-methyl­imidazolium)acetate bromide and CoBr2. The title compound consists of an imidazolium-based dication and a tetra­bromido­cobaltate(II) complex anion, which are connected via C—H...Br inter­actions in the crystal. The dihedral angle between the imidazolium rings in the cation is 72.89 (16)°. The CoII ion in the anion is coordinated tetra­hedrally by four bromide ligands [Co—Br = 2.4025 (5)–2.4091 (5) Å and Br—Co—Br = 106.224 (17)–113.893 (17)°]. The compound exhibits a high melting point (>300°C) and is a light-blue solid under ambient conditions.

2014, Dura, L., Spannenberg, A., Beweries, T.

The asymmetric unit of the title compound, [Co(C24H30N2P2)(CO)3][Co(CO)4]·0.25C7H8, consists of two crystallographically independent cations with similar conformations, two anions, and one-half of a toluene molecule disordered about an inversion centre. In the cations, a Co/P/N/P four-membered slightly bent metallacycle is the key structural element. The pendant NH group is not coordinated to the CoI atom, which displays a distorted trigonal-bipyramidal coordination geometry. Weak interionic hydrogen bonds are observed between the NH groups and a carbonyl group of the tetrahedral [Co(CO)4]- anions.