Anke Flemming

Niobium alcoholate clusters with an octahedral arrangement of metal atoms: [K(CH3OH)4]2 [Nb6(OCH3)18] and [Na([18]crown-6)(C2H5OH)2]2 [Nb6(OC2H5)12(NCS)6].

Complete exchange: [M(6)X(12)] type cluster compounds with an octahedral M(6) metal atom arrangement, which is completely surrounded by alcoholato ligands, were unknown until now. The first representatives are prepared containing a [Nb(6)(OR)(12)](4+) unit (R = CH(3) or C(2)H(5)). They are accessible at elevated temperatures from strongly basic alcoholate solutions of [Nb(6)Cl(12)](2+)-containing precursors. C gray, H white, K turquoise, Nb blue, O red.

Synthesis and Radiofluorination of Iodophenyl Esters as Tool for the Traceless Staudinger Ligation

A new synthetic pathway for the preparation of ω-functionalized 2-iodophenyl esters as starting materials for the synthesis of substituted phosphanes is described. A radiolabeling of these esters with fluorine-18 has led to building blocks which were reacted with HPPh2 in a Pd-catalyzed P-C cross coupling to establish new phosphanes. These compounds can be applied as mild and bioorthogonal radiolabeling agents by means of the traceless Staudinger ligation. A route to access this class of compounds has been established. Graphical Abstract Synthesis and Radiofluorination of Iodophenyl Esters as Tool for the Traceless Staudinger Ligation

Twisted oxygen-containing oligosilanes : unprecedented examples of σ-n mixed conjugated systems

Twisting the silicon backbone conformation in oxygen containing oligosilanes towards dihedral angles of 120–130° either by intramolecular hydrogen bonding or incorporation into a covalently bonded ring system effectively extends the delocalization of electrons in these σ–n mixed conjugated systems.

(3R*,5′S*)-6,7-Dimeth­oxy-3-(4′-meth­oxy-6′-methyl-5′,6′,7′,8′-tetra­hydro-1,3-dioxolo[4,5-g]isoquinolin-5′-yl)isobenzofuran-1(3H)-one (racemic α-noscapine)

In the racemic title compound, C22H23NO7, the dihedral angle between the fused ring systems is 51.87 (6)°. Two of the methoxy groups are disordered over two orientations in 0.688 (5):0.312 (5) and 0.672 (15):0.328 (15) ratios. In the crystal, weak C—H⋯O interactions link the molecules.

Crystal structure of 2-(di­phenyl­phos­phanyl)phenyl 4-(hy­droxy­meth­yl)benzoate

The title compound, C26H21O3P, was obtained as by-product due to the hydrolysis of the desired tosylated compound. The dihedral angles between the three aromatic rings attached to the P atom lie in the range 78.1 (1)–87.6 (1)°. The hydroxymethyl group is disordered between two conformations in a 0.719 (9):0.281 (9) ratio. The hydroxy H atom is not involved in intermolecular interactions, while the hydroxy O atom serves as a donor for weak C—H⋯O hydrogen bonds, which link the molecules into chains propagating in [0-11].