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Monoaryne and monoisobenzofuran analogues of a C(3v)-symmetrical tribenzotriquinacene (TBTQ) were generated in situ and trapped with various dienes and dienophiles, respectively. In this way, a series of single-wing extended TBTQ derivatives bearing the bowl-shaped TBTQ unit in different topographical expositions have become accessible. This includes some novel tribenzotriquinacene "dimers", in which two TBTQ bowls are attached in syn- or anti-orientation at the terminal positions of rigid linker units. Several of these compounds have been characterized by both spectroscopy and X-ray structural analysis. The efficient access to the TBTQ "dimers" may lay a useful foundation for further studies of novel container compounds and supramolecular architectures.

High stereoselectivity in an aqueous medium, the introduction of tri-oxygenated functional groups, and the efficient construction of at least two chiral centers are features of this transformation.

The novel double-stage convergent synthesis of a new class of polyisoprene terpenoid (PIPTP) dendrons is described. PIPTP dendrons bear a highly branched aliphatic hydrocarbon skeleton and a hydrophilic hydroxy focal point functionality. These dendrons have the specific formula C((5×2)(G+1)(-5))H((5×2)(G+2)(-8))O, and each dendritic layer is constructed from an isoprene unit. The key branching steps involve a double alkyl-metal addition to an ester functionality, followed by deoxygenation of the resulting tertiary alcohol by triethylsilane and trifluoroacetic acid, then hydrogenation or hydrogenolysis. The dendrons were also attached to oligo(phenylene ethynylene)s (OPEs) so as to function as protective shells to allow fine tuning of the nanoscopic environment around the OPE moiety, and to exert precise control of the packing density and intermolecular interaction between the OPE cores. Fluorescence quantum yield data reveal that the OPE core is better encapsulated by the PIPTP dendrons than by Fréchet dendrons.

High stereoselectivity in an aqueous medium, the introduction of tri-oxygenated functional groups, and the efficient construction of at least two chiral centers are features of this transformation.

A concise enantioselective synthesis of malyngamide W (1) and its 2′-epimer was described. The strategy was based on three key steps: (1) ozonolysis of compound 11 which was derived from (R)-(−)-carvone 8, followed by copper-iron-catalyzed rearrangement to give the key cyclohex-2-enone intermediate 5, (2) Nozaki–Hiyama–Kishi coupling reaction between aldehyde 4 and iodide 14 to afford alcohol 3, and (3) asymmetric (R)-CBS reduction of the ketone functionality in compound 21 to establish the C-2′ chiral center in the target compound 1. The absolute configuration of malyngamide W (1) was thus confirmed via the synthesis of 1 and 2′-epi-1.

New tribenzotriquinacene (TBTQ) hosts bearing six-fold peripheral benzofuran functionalization have been synthesized. The three polycondensed arene wings were shown to operate optically independently and to generate deeply bowl-shaped C(3v)-symmetrical frameworks that act as relatively weak hosts toward C(60), as revealed by (1)H NMR spectroscopy.

Understanding the effects of intermolecular interactions on the charge-transport properties of metal/ molecule/metal junctions is an impor- tant step towards using individual mol- ecules as building blocks for electronic devices. This work reports a systematic electron-transport investigation on a series of "core-shell"-structured oligo(- phenylene ethynylene) (Gn-OPE) mo- lecular wires. By using dendrimers of different generations as insulating "shells", the intermolecular p-p inter- actions between the OPE "cores" can be precisely controlled in single-com- ponent monolayers. Three techniques are used to evaluate the electron-trans- port properties of the Au/Gn-OPE/Au molecular junctions, including crossed- wire junction, scanning tunneling spec- troscopy (STS), and scanning tunneling microscope (STM) break-junction tech- niques. The STM break-junction mea- surement reveals that the electron- transport pathways are strongly affect- ed by the size of the side groups. When the side groups are small, electron transport could occur through three pathways, including through single- molecule junctions, double-molecule junctions, and molecular bridges be- tween adjacent molecules formed by aromatic p-p coupling. The dendrimer shells effectively prohibit the p-p cou- pling effect, but at the same time, very large dendrimer side groups may hinder the formation of AuS bonds. A first-generation dendrimer acts as an optimal shell that only allows electron transport through the single-molecule junction pathway, and forbids the other undesired pathways. It is demonstrated that the dendrimer-based core-shell strategy allows the single-molecule conductance to be probed in a homo- genous monolayer without the influ- ence of intermolecular p-p interac- tions.

A series of 1,4-bis[2,2-bis(4-alkoxyphenyl)vinyl]benzene molecules with aggregation-induced emission (AIE) activity were synthesized. The conformations and packing arrangements of these molecules in the solid state can be adjusted by changing the side chains, which subsequently modulates their solid-state emission. The fluorescence quantum yield of 1e with the n-C(6)H(13) side chain in the solid state could reach up to 60.3% in the solid state.

Alkyl and aryl substituted 1,2,3-butatrienes can be prepared in good yields via tetrabutylammonium fluoride induced 1,4-eliminations of 1-acetoxy-4-trimethylsilylbut-2-ynes at –10 °C.

Substituted 1,3,5-hexatrienes 7 can be prepared in excellent yields and with good stereoselectivity from diallylic sulfones 6 employing a modified Ramberg–Backlund reaction.

Reaction of the lithium or cerium(III) anion of 3-alkyl or 3-aryl substituted 3-trimethylsilylprop-1-yne 1 with aldehydes or ketones afforded 1-hydroxy-4-trimethylsilylbut-2-ynes 2 in good yields. Conversion of the silyl prop-2-ynylic alcohols 2 into the corresponding acetates 3 followed by tetrabutylammonium fluoride-induced, 1,4-elimination gave alkyl and aryl substituted buta-1,2,3-trienes 4 in good yields.

The novel convergent growth approach to dendritic macromolecules is described. Polyether dendritic sectors [G-na]-OH from the first to the fourth generations, respectively, were prepared by this approach from readily available starting material.

Enantiomerically pure tribenzotriquinacenes (TBTQs) bearing two monofunctionalized aromatic nuclei were synthesized for the first time and their optical properties and absolute configuration determined. A remarkably regioselective bis-formylation of the fully bridgehead methylated parent TBTQ hydrocarbon with MeOCHCl(2)/TiCl(4) afforded a mixture of two C(s)-symmetrical (achiral) difunctionalized derivatives together with one C(1)-symmetrical (chiral) isomer. Reduction and subsequent column chromatography furnished the three respective benzylic TBTQ dialcohols. Optical resolution of the racemic 2,6-bis(hydroxymethyl) derivative was achieved via the diastereomeric (R)-1,1'-bi-2-naphthol ethers and the absolute configuration of the enantiomers was determined by CD exciton model analysis. The electronic circular dichroism (ECD) spectra and the specific rotation of the enantiomers were found to agree with the results of DFT calculations. Among the C(s)-symmetrical isomers, the "proximal" 2,11-dialdehyde and the corresponding benzylic dialcohol were identified by 2D NMR spectroscopy and X-ray crystallographic analysis, respectively, and used as the starting point for the synthesis of several novel dithiametacyclophanes. These include the first "dimeric" tribenzotriquinacene-based cyclophanes bearing the bowls of the two TBTQ units attached to each other in a syn (concave-concave) or anti (convex-concave) configuration. The usefulness of such thiacyclophanes as fluorescent chemosensors for different metal ions is also demonstrated.

Two new natural derivatives of pomolic acid, 3,11-dioxo-19α-hydroxyurs-12-en-28-oic acid and 28-O-β- D -glucopyranosyl-pomolic acid ester, have been isolated from the roots of Sanguisorba officinalis.

Two series of new oligothiophene-pentacene hybrid compounds were successfully synthesized and characterized, which consist of pentacene and anthradithiophene skeletons modified by different oligothienyl groups at 6,13 sites or 5,11 sites, respectively. Their optical, thermal, and electrochemical properties show regular variations with the length change of the side groups. These materials exhibit much higher solubility and significantly improved thermal and photooxidation stabilities compared with unmodified pentacene and anthradithiophene.

A series of systematically modified porphyrin esters, compounds 1-6, with multiple, permanent positive charges introduced at the meso-positions via N-methylated 4-, 3-, or 2-pyridyl moieties, were prepared and characterized. Their singlet-oxygen production, CT-DNA-binding properties, and plasmid-DNA photocleavage propensities were determined spectroscopically and by gel electrophoresis, and compared to those of the known, fourfold-charged parent porphyrin 4,4',4'',4'''-porphyrin-5,10,15,20-tetrayltetrakis(1-methylpyridinium) (TMPyP4). Some interesting structure-activity relationships could be established to rationalize effects affecting DNA binding mode and cleavage ability.

NaHSO 4 ·SiO 2 was used as an efficient heterogeneous catalyst for both the formation and the cleavage of benzylidene -acetals. This catalyst is compatible with many functional or protective groups. Under different solvent systems, either the formation or the cleavage of benzylidene acetals was carried out smoothly in -excellent yields and with good chemoselectivity.

The enantioselective synthesis of the previously proposed structure of malyngamide U (1) was accomplished in 18 steps from (S)-(+)-carvone. The key steps involved a hydroxymethylation of (S)-(+)-carvone and an asymmetric Henry reaction of aldehyde (+)-5, as well as condensation with the acid 3. The 1H and 13C NMR data of the synthetic compound 1 were not consistent with the data of the reported malyngamide U. The C-2‘ epimer of compound 1 was therefore synthesized by a similar reaction sequence. While the NMR data of C-2‘ epimer 23 were in full agreement with those of the reported product, the discrepancy in the specific rotation data suggested the correct structure of malyngamide U should be structure 2, in which the absolute configuration of the amine part was enantiomeric with that in compound 23. Then the correct absolute configuration of revised malyngamide U (2) was confirmed by the similar synthesis from (R)-(-)-carvone.

Alkyl glucoside 1 and aryl glycosides 2–4 were highly stereospecifically synthesized over 4–6 steps from commercially available starting materials. The coupling reaction of the acetobromo-α-D-glucose with the unprotective dihydroxy aglycon in the presence of silver oxide, or with aromatic aglycon in the presence of sodium hydroxide produced the key intermediate. Only β-configuration glycosides were formed in this procedure. The synthesis of all these glycosides was reported for the first time.

To investigate the effect of nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway on cochlear sensitivity. Methods Ten groups of guinea pigs were treated with the following solutions by whole cochlear perfusion for 2 hours: (1) Artificial perilymph; (2) L-arginine; 93) Ca(2+)-ATPase inhibitor; (4) Ca(2+)-ATPase inhibitor + L-arginine; (5) Ca(2+)-ATPase inhibitor + cGMP; (6) Ca 2+ ATPase inhibitor + L-arginine + Non-selective NOS inhibitor; (7) eNOS inhibitor; (8) eNOS inhibitor + Ca(2+)-ATPase inhibitor; (9) eNOS inhibitor + Ca(2+)-ATPase inhibitor + L-arginine; (10) eNOS inhibitor + Ca(2+)-ATPase inhibitor + L-arginine + nNOS inhibitor. The compound action potential (CAP) and cochlea microphonics (CM) were measured to assess the changes of cochlear sensitivity. After the perfusion, the cochleae were harvested and prepared for transmission electron microscopy.The average threshold shift of CAP after perfusion Ca(2+)-ATPase inhibitor was 28.5 dB, and it was improved in group 4 with 9 dB by L-arginine, similar with group 5. The threshold shift of CAP in group 8 was 42.5 dB, and it decreased in group 9 by L-arginine, on this foundation nNOS inhibitor was added, increased threshold shift of CAP was 6.5 dB, similar with group 8. The results indicated that L-arginine could rivalry the role of Ca(2+)-ATPase inhibitor through the path of NO-cGMP. Transmission electron microscopy showed that Ca(2+)-ATPase inhibitor + L-arginine combined administration resulted in less vacuolization in out hair cell than that treated with Ca(2+)-ATPase inhibitor only.The NO-cGMP pathway could regulate cochlear sensitivity; L-arginine may improve the function of Corti's organ via nNOS, and they indicate an important role of supporting cells in the modulation of cochlear function.

The first total synthesis of (±)-palstatin was achieved from commercially available 5-bromovanallin and 2,4,6-trihydroxyacetophenone. SeO2 promoted oxidative cyclization reaction and Ag2O catalyzed oxidative coupling reaction served as the key steps in the synthesis successfully.

Phebaclavin A (1) and C (2) were synthesized in 60% and 58% total yields over 5 steps from commercially available starting meterials respectively. The synthesis feature was usage of the Wittig reaction twice and solvent-free cyclizing reaction as the key steps.

Twelve trans-dicationic pyridium porphyrins appending different peripheral substituents were synthesized and their abilities to bind and cleave DNA under irradiation have been investigated. Their binding modes to DNA were studied by UV-vis spectroscopy, circular dichroism. The apparent constants were measured by EB competitive fluorescence method and most of them were in the range of 10(4)-10(5) M(-1). We found that both the position of positive charges and steric hindrance could greatly influence their binding affinities and modes to DNA, and then affect their photocleaving abilities to DNA.

Three water-soluble DNA cross-linking phenol quaternary ammonium derivatives 3, 4, and 5 could inhibit the transcription in vitro by photoactivation. DNA interstrand cross-linking action might be the key factor to inhibit transcription by these compounds. Further tumor cell apoptosis was observed by flow cytometry it indicated that cross-linking agent 5 could significantly induce the late apoptosis of tumor cells.

Hexabromotribenzotriquinacenes and octabromotetra-benzo[5.5.5.5]fenestranes undergo highly efficient multiple Stille cross-coupling reactions, yielding building blocks for extended convex/concave and saddle-shaped Molecular scaffolds, respectively.

Two new diterpene glycosides, named rufusoside A and B were isolated from Senecio rufus. Their structures have been established as ent-15α-(α- l -arabinopyranosyloxyl)- kaur-16-en-19-oic acid and ent-15α-(ζ- l -arabinopyranosyloxyl)-kaur-16-en-19- oic acid-β- d -glucopyranosyl ester, respectively, mainly through interpretation of their spectroscopic data.

A Lewis acid promoted tandem reaction of epoxide rearrangement and intramolecular [3+2] cycloaddition reaction of cyclopropanes with carbonyls formed by epoxide rearrangement in situ, which were obtained with difficulty by a general method, is reported. A wide variety of fused- and spiro-oxa-[n.2.1] skeletons could be efficiently constructed.

The title compound, C18H17NO4, was obtained accidentally through acid-catalysed aromatization of a phthalimide-substituted 2-(1-hydroxyethyl)cyclohex-2-enone. It exhibits an intramolecular O—H...Oc (c = carbonyl) hydrogen bond and forms a three-dimensional network structure via π–π stacking interactions between adjacent benzene rings (phthalimide-to-phenylene and phthalimide-to-phthalimide), with centroid–centroid distances of 3.8262 (6) and 3.6245 (5) Å.

The transformation of 1,6-enynes into bridged bicyclic systems was accomplished for the first time by a copper(I)-catalyzed tandem cycloaddition reaction. The reaction provides a straightforward approach for the synthesis of structurally diverse, strained and bridged bicycles in good yields with moderate to excellent diastereoselectivities.

A series of tridentate N,N,N-nickel complexes bearing 2-(1H-2-benzimidazolyl)-6-(1-(arylimino)ethyl)pyridines was synthesized and characterized by elemental and IR spectroscopic analysis. The molecular structures of representative complexes were determined by single-crystal diffraction, and these were found to have a six-coordinate distorted octahedral geometry around the Ni centre. On treatment with Et2AlCl, all nickel complexes exhibited good catalytic activities up to 106 g mol–1(Ni) h–1 for ethylene oligomerization with major dimerization. The steric and electronic effects on catalytic activities of metal complexes as well as the influence of various reaction parameters were carefully investigated.

Superhydrophobic surfaces were prepared on Ti/Si substrates via the fabrication of a platinum (Pt) nanowire array. The Pt nanowire array was obtained by dc electrodeposition of Pt into the pores of an anodic aluminium oxide (AAO) template on the substrate followed by the removal of the template. Transmission electron microscopy (TEM) examination demonstrated that all the nanowires have uniform diameter of about 30 nm. Field emission scanning electron microscopy (FE-SEM) showed that the structures at both the micrometre scale and nanometre scale bestowed the prerequisite roughness on the surfaces. The chemical surface modification made the Pt nanowire array superhydrophobic. The surface modified Pt nanowire array exhibited superhydrophobicity even in corrosive solutions over a wide pH range, such as acidic or basic solutions. The results demonstrated that the Pt nanowire array will have good potential applications in the preparation of superhydrophobic surfaces.

The title compound, C35H31NO4, which is a new amide podand ligand, contains an intra­molecular hydrogen bond between the phen­oxy O atom and the amide N atom. The packing is stabilized by weak C—H⋯O hydrogen-bonding inter­actions.

We report here that phenol derivatives with two and four quaternary ammoniums were synthesized and their abilities to bind and cross-link DNA were investigated. Thermal denaturizing studies indicated that derivatives possess similar DNA binding abilities and gel electrophoresis revealed that more charges (series B) and electronic donation substitute linkers (like -S-) dramatically increase the DNA cross-linking abilities.