Nengfang She

An efficient synthesis of hydantoins via sustainable integration of coupled domino processes.

A highly efficient synthesis of hydantoins has been developed from simple and commercially available 1,3-dicarbonyl compounds, ureas, and methyl ketones or terminal aryl alkenes. This protocol involves a sustainable integration of two coupled domino processes: iodine-promoted synthesis of unsymmetrical 1,4-enediones (domino I) and the sequential transformation into hydantoins (domino II).

Sensor for Nitrophenol Based on a Fluorescent Molecular Clip

We report the synthesis, X-ray crystal structure, and photophysics of a fluorescent molecular clip (1). Binding studies of 1 toward phenols 2a-j were carried out using fluorescence, (1)H NMR, and IR spectroscopy, which revealed a high affinity and selectivity for 4-nitrophenol (2a) due to formation of the 1.2a complex driven by H-bonding and pi-pi stacking interactions.

Supramolecular Rhombic Grids Formed from Bimolecular Building Blocks

A programmed assembly process produces rhombic grid networks from compounds L1-L4 in the crystal by pi-pi stacking interactions that generate a bimolecular grid synthon, which undergoes further NH...N hydrogen-bond-mediated assembly.

Novel Fluorescent Molecular Clips: Selective Recognition Towards Fe3+ in Aqueous Solution

In this paper, we report the synthesis, characterization and Fe3+-sensing properties of a series of new artificial fluorescent molecular clips, and structure of clip 1 is confirmed by X-ray crystallography. All these molecular clips had the ability to bind and sense Fe3+ selectively through decrease fluorescence responses in THF-MeOH-Water. Fluorimetric titration experiment indicated that the quenching of these compounds’ fluorescence upon Fe3+ probably arises from the electron/energy transfer between Fe3+ and the excited chemosensors. The limit of detection, linear concentration range and selectivity of the fluorescent molecular clips were evaluated in this study as well.

Tetrameric molecular bowl assembled from glycoluril building blocks

Glycoluril derivative--whose bulky Ph-C[triple bond]C- substituents prevent formation of H-bonded tapes--undergoes solvent dependent assembly in the crystal; a tetrameric molecular bowl is formed by R(24) H-bonding interactions from CH(2)Cl(2) whereas DMF results in H-bond dimerization followed by oligomerization via C-H...pi interactions.

Two-dimensional hydrogen-bonded networks in two novel glycoluril derivatives.

Two new glycoluril derivatives, namely diethyl 6-ethyl-1,4-dioxo-1,2,2a,3,4,6,7,7b-octahydro-5H-2,3,4a,6,7a-pentaazacyclopenta[cd]indene-2a,7b-dicarboxylate, C(14)H(21)N(5)O(6), (I), and 6-ethyl-2a,7b-diphenyl-1,2,2a,3,4,6,7,7b-octahydro-5H-2,3,4a,6,7a-pentaazacyclopenta[cd]indene-1,4-dione, C(20)H(21)N(5)O(2), (II), both bearing two free syn-urea NH groups and two ureidyl C=O groups, assemble the same one-dimensional chains in the solid state running parallel to the [010] direction via N-H...O hydrogen bonds. Furthermore, the chains of (I) are linked together into two-dimensional networks via C-H...O hydrogen bonds.

(2RS,3SR)‐Diethyl 2,3‐bis­(1,3‐benzodioxole‐5‐carbon­yl)succinate

In the centrosymmetric title compound, C24H22O10, the two aromatic rings are parallel to each other. The crystal packing is stabilized mainly by van der Waals forces.

Diethyl 7,8-dibromo-4,11-dioxo-11b,11c-dihydro-5H,10H-2-oxa-3a,4a,10a,11a-tetra-azabenz[f]indeno[2,1,7,7a-ija]azulene-11b,11c-dicarboxyl-ate.

The title compound, C20H20Br2N4O7, is an intermediate for molecular clips. The seven- and six-membered rings have chair conformations, while the five-membered rings adopt envelope conformations. In the crystal structure, weak C—H⋯O and C—H⋯Br interactions link the molecules into a three-dimensional network. The ethoxy and ethyl groups are disordered over two orientations, with occupancy ratios of 0.735 (16):0.265 (16) and 0.51 (2):0.49 (2), respectively.

trans-1,2,3-Tris(4-methoxy­benzo­yl)cyclo­propane

In the title compound, C27H24O6, the packing of the molecules is mainly governed by C—H⋯O interactions.