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The first neutron diffraction study of a single crystal containing uranyl peroxide nanoclusters is reported for pyrophosphate-functionalized Na44K6[(UO2)24(O2)24(P2O7)12][IO3]2·140H2O (1). Relative to earlier X-ray studies, neutron diffraction provides superior information concerning the positions of H atoms and lighter counterions. Hydrogen positions have been assigned and reveal an extensive network of H-bonds; notably, most O atoms present in the anionic cluster accept H-bonds from surrounding H2O molecules, and none of the surface-bound O atoms are protonated. The D4h symmetry of the cage is consistent with the presence of six encapsulated K cations, which appear to stabilize the lower symmetry variant of this cluster. 31P NMR measurements demonstrate retention of this symmetry in solution, while in situ 31P NMR studies suggest an acid-catalyzed mechanism for the assembly of 1 across a wide range of pH values.

(Et2NH2)2[CuCl4] crystallizes in the orthorhombic space group P212121 with Z = 8 (single crystal XRD).

The Diels-Alder dimer of cyclopentadiene carboxylate, Thiele's acid has conformational properties that make it attractive as a molecular scaffold for applications in supramolecular and biological chemistry. However, a lack of known reaction methodology for derivatives of Thiele's acid (or the corresponding esters) has hampered its utilization in these fields. We describe an improved preparation of Thiele's esters and survey the chemistry of these versatile intermediates. As part of this effort, we also describe the synthesis of a suite of Thiele's acid (or ester) analogues spanning a broad range of cleft angles.

The regioselective reaction of 2,4-dichloro-5-nitropyrimidine (I) with tertiary amines (II) and (VI) leads to pyrimidin-2-amines (III) and (VII), resp., whilst the reaction with N-methylpyrrolidine gives rise to unexpected chloride (V).

The direct access to N-acyl hydrazones is rendered possible by hexamethylphosphorous mediated condensation of various 1,2-dicarbonyl compounds with dialkylazodicarboxylates.

Upon variation of the steric and electronic properties of the starting sulfolenes four unique bi- or tricyclic ring-systems are constructed as single diastereomers with up to five stereogenic centers.

A complementary approach toward nitrone construction that circumvents a conventional condensation strategy by exploiting the unusual reactivity of 1,2-dicarbonyls with phosphines is reported.

The reaction of oximes (I) with the chlorophosphite (II) and tosyl azide is examined resulting in the formation of N-tosyl amidines through a Beckmann-type process.

The intermediate borane reagents react with carbonyl compounds to afford homoallylic and homopropargylic alcohols with low to excellent enantioselectivity.

Single crystals of (Me4N)4 [UO2(CO3)3]·8H2O are grown by slow evaporation (25 °C, 6 weeks) of an aqueous solution of uranyl 1-hydroxyethane-1,1-diphosphonate and Me4NOH.

The structures of the new uranyl and neptunyl fluoroborates are determined by single crystal XRD.

A simple and efficient method for replacing Ge atoms in deltahedral Ge94- clusters with Sb or Bi is reported.

The empty and Ni-centered Ge9 and Sn9 clusters react with TlCp and add a tenth Tl-vertex to form bicapped square antiprismatic closo-clusters [M9Tl]3- (M: Ge, Sn) and [Ni@M9Tl]3-.

The title molecule, C17H10N2O2, is a synthetic precursor to the cytotoxic marine alkaloid ascididemin and is also structurally related to cleistopholine, a plant-derived antifungal agent. The molecule was found to be essentially planar with the only significant deviations from planarity being for the quinone O atoms.

A survey of individual specimens of northern Papua New Guinea derived Cacospongia mycofijiensis has yielded novel sesquiterpenes, aignopsanoic acid A (1), methyl aignopsanoate A (2), and isoaignopsanoic acid A (3). The structures and absolute configurations of 1-3 were established using NMR data, X-ray crystallography results, and an analysis of CD properties. Two of these metabolites, 1 and 2, were moderately active against Trypanosoma brucei, the parasite responsible for sleeping sickness.

Our 2004 disclosure of the amino hemiketal-containing spiroleucettadine was met with keen interest by the natural products and synthetic communities. As repeated efforts to synthesize spiroleucettadine failed and questions regarding the original structure elucidation process arose, evidence mounted against the validity of the proposed structure. The low ratio of H/C in the core of spiroleucattadine complicated the original structure elucidation process. Speculation prompted a reisolation of spiroleucettadine from an untouched portion of the original Luecetta collection and a thorough analysis of analytical data. In addition, a systematic analysis of candidate structures was performed via density functional theory (DFT) calculations; a favored high scoring structure 1b was ultimately confirmed to be spiroleucettadine via X-ray analysis of crystalline spiroleucettadine and reinforced the validity of DFT calculations in structure elucidation. We present the revised structure of spiroleucettadine, a bicyclic sponge alkaloid with a scarcity of H-atoms in its core.

A reinvestigation of a Fijian collection of Cacospongia mycofijiensis has yielded the known mycothiazole and a novel heterocyclic, CTP-431 (1). Its structure including absolute configuration as 8R,9R,10S,13S was established using NMR data, calculated DFT 13C chemical shifts and results from X-ray crystallography. It is possible that the tricyclic skeleton of CTP-431 (1) is biosynthetically related to the macrolide latrunculin A, however the thiopyrone moiety of 1 has no previous precedent in natural products chemistry.