Construction and Modification of Nitrogen-Rich Polycyclic Frameworks: A Promising Fused Tricyclic Host-Guest Energetic Material with Heat Resistance, High Energy, and Low Sensitivity.

The construction and modification of novel energetic frameworks to achieve an ideal balance between high energy density and good stability are a continuous pursuit for researchers. In this work, a fused [5,6,5]-tricyclic framework was utilized as the energetic host to encapsulate the oxidant molecules for the first time. A series of new pyridazine-based [5,6] and [5,6,5] fused polycyclic nitrogen-rich skeletons and their derivatives were designed and synthesized.

MeSiBr-promoted cascade electrophilic thiocyanation/cyclization of -alkynylanilines to synthesize indole derivatives.

A Lewis acid-promoted electrophilic thiocyanation/cyclization of -alkynylanilines for the synthesis of indole derivatives has been developed. The reaction utilizes MeSiBr as the Lewis acid and -thiocyanatosuccinimide as the thiocyanation reagent. A series of 2-aryl-3-thiocyanato indoles were prepared in moderate to high yields under mild conditions without metals and oxidants.

Organophotocatalytic Remote Thiocyanation Reaction via Ring-Opening Functionalization of Cycloalkanols.

The remote C(sp)-SCN bond formation via ring-opening functionalization of cycloalkanols with N-thiocyanatosaccharin as the precursor of SCN radicals and pyrylium salt as the organic photocatalyst under visible light has been developed. Thus, various terminal keto thiocyanates were prepared without transition metals and oxidants in moderate to good yields. The simplicity, wide substrate scope and mild conditions feature its synthetic application capability.

Copper(I)-catalyzed electrophilic thiocyanation/dearomatization/spirocyclization of benzofurans to synthesize benzannulated spiroketals.

A Lewis acid-catalyzed electrophilic dearomatizative thiocyanation and cyclization of benzofurans with -thiocyanatosuccinimide has been accomplished by Lewis acid catalysis with CuOTf under mild conditions. It was suggested that the electrophilic thiocyanating reagent was activated by CuOTf, and difunctionalization was achieved through a thiocyanation/spirocyclization pathway. Thus, a series of thiocyanato-containing spiroketals were obtained in moderate to high yields.

Synthesis of thiocyanato-containing phenanthrenes and dihydronaphthalenes Lewis acid-activated tandem electrophilic thiocyanation/carbocyclization of alkynes.

A tandem electrophilic thiocyanation and cyclization of arene-alkynes has been developed under mild conditions, affording thiocyanato-substituted phenanthrenes, dihydronaphthalenes, 2-chromenes and dihydroquinolines in moderate to excellent yields. This reaction provides an efficient protocol for the construction of C-SCN and C-C bonds in one step. In this transformation, -thiocyanato reagent serves as a convenient precursor to transfer SCN in the presence of trimethylchlorosilane, and the cyclization exhibited exclusive selectivity.

Electrophilic Thiocyanato Reagent Assisted Oxa-Michael/Thiocyanation of α,β-Unsaturated Ketones.

A route for thiocyanation-functionalization of the electron-deficient C═C double bond was developed. Regioselective thiocyanation-etherification of α,β-unsaturated ketones was achieved. The desired products were obtained in moderate to high yields under mild conditions.

AIBN-initiated direct thiocyanation of benzylic sp C-H with -thiocyanatosaccharin.

Direct thiocyanations of benzylic compounds have been implemented. Here, a new strategy, involving a free radical reaction pathway initiated by AIBN, was used to construct the benzylic sp C-SCN bond. In this way, the disadvantage of other strategies involving introducing leaving groups in advance to synthesize benzyl thiocyanate compounds was overcome.

Atom-Economical Thiocyanation-Amination of Alkynes with -Thiocyanato-Dibenzenesulfonimide.

A highly regioselective protocol for intermolecular thiocyanation-amination of alkynes by -thiocyano-dibenzenesulfonimide (NTSI) as the SCN and nitrogen sources has been developed. A C-S bond and C-N bond are simultaneously constructed in only one step. The reaction under simple mild conditions features a broad substrate scope, atom economy, high yields (up to 94%), and excellent functional group tolerance.

Lewis Acid-Catalyzed Asymmetric Selenocyanation of β-Ketoesters with -Selenocyanatosaccharin.

The first electrophilic asymmetric selenocyanation has been achieved in the presence of Ni(OTf) and (,)-DBFOX/Ph using -selenocyanatosaccharin as the new selenocyanation reagent. Thus, a series of α-selenocyanato-β-keto esters were synthesized with high yields (up to 99%) and good ee values (up to 92% ee). The readily preparation of the reagent and high enantioselectivity make this methodology much practical for the synthesis of chiral selenocyanates.

N-Thiocyanato-dibenzenesulfonimide: a new electrophilic thiocyanating reagent with enhanced reactivity.

A novel electrophilic thiocyanating reagent, N-thiocyanato-dibenzenesulfonimide, was prepared and exhibited enhanced electrophilicity with a wide scope of substrates. Thus, it reacted with activated aromatics such as phenols, indoles, anilines and anisoles without a catalyst giving the corresponding thicyanate derivatives in high yields, while TfOH for unactivated arenes and hetero aromatics and Zn(OTf) for ketones was used as the catalyst, respectively. It is noteworthy that internal alkenes and styrenes were bifunctionalized giving 1,2-amino thiocyanates in high yields.

Organocatalyzed Asymmetric α-Thiocyanation of Oxindoles: Synthesis of Chiral Tertiary 3-Thiocyanatoxindoles.

An enantioselective thiocyanation of oxindoles has been developed for the first time using a bifunctional cinchona-derived organo-catalyst and N-thiocyanatophthalimide as the electrophilic thiocyanation source in the presence of 2-naphthol as the additive. Various enantioenriched 3,3'-disubstituted oxindoles with SCN-containing quaternary carbon stereocenters were synthesized under mild conditions in high yields (up to 99%) and good enantioselectivities (up to 6:94 er).

Upregulation of Nav1.6 expression in the rostral ventrolateral medulla of stress-induced hypertensive rats.

The rostral ventrolateral medulla (RVLM) plays a key role in mediating the development of stress-induced hypertension (SIH) by excitation and/or inhibition of sympathetic preganglionic neurons. The voltage-gated sodium channel Nav1.6 has been found to contribute to neuronal hyperexcitability.

The Chemistry and Properties of Energetic Materials Bearing [1,2,4]Triazolo[4,3-b][1,2,4,5]tetrazine Fused Rings.

Treatment of heterocyclic amines featuring fused rings of [1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine with fuming HNO /P O leads to six fully characterized explosives through multiple nitration and reduction or oxidation mechanism. Thus, 4-nitro-N-(3-nitro[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-yl)-1,2,5-oxadiazol-3-amine (3 b, TTDNF) showed high performance (D=9180 m s , P=36.7 GPa) and low impact sensitivity (IS>40 J) while N-([1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-yl)-3-nitro-1,2,4-oxadiazol-5-amine (4 a, TTNOA) exhibited a potential cast explosive component with low melting point at 88.

Enantioselective Organocatalyzed Direct α-Thiocyanation of Cyclic β-Ketoesters by N-Thiocyanatophthalimide.

A new electrophilic thiocyanation reagent, N-thiocyanatophthalimide, was synthesized and applied to the first example of catalytic asymmetric electrophilic α-thiocyanation of various cyclic β-ketoesters by the bifunctional cinchona alkaloid catalysis. Thus, a variety of chiral α-thiocyanato β-ketoesters with a quaternary carbon center have been achieved in excellent yields (up to 99%) and high enantioselectivities (up to 94% ee) in a convenient manner.

N-Thiocyanatosaccharin: A "Sweet" Electrophilic Thiocyanation Reagent and the Synthetic Applications.

N-Thiocyanatosaccharin (R) was readily prepared from the sweet additive Saccharin in two steps with a 71% overall yield. By applying this new reagent to diverse nucleophiles such as benzothiophenes, indoles, oxindoles, aromatic amines, phenols, β-keto carbonyl compounds, and aromatic ketones, a novel electrophilic thiocyanation reaction was achieved with high yields (up to 99%). The potential recycling of Saccharin, the wide scope of substrates, and the mild reaction conditions made this protocol much more practical.

Enantioselective electrophilic cyanation of β-keto amides catalysed by a cinchona organocatalyst.

An operationally simple protocol for the enantioselective electrophilic α-cyanation of β-keto amides catalyzed by cinchona-derived catalysts has been demonstrated. The resulting products could be obtained with good to high enantioselectivities (up to 88% ee) and with excellent yields (up to 94%) by employing the mild active 4-acetylphenyl cyanate as the cationic cyano source in the catalytic asymmetric α-cyanation reaction.

Catalytic Asymmetric Electrophilic Cyanation of 3-Substituted Oxindoles.

The first example of catalytic asymmetric electrophilic cyanation of 3-substituted oxindoles has been achieved using readily accessible 4-acetylphenyl cyanate as the cyano source. Thus, a series of all-carbon quaternary center 3-aryl-3-cyano oxindoles were prepared using a zinc complex of a chiral pincer ligand as the catalyst in high yields (up to 95%) and excellent enantioselectivities (up to >99% ee) in the presence of 4 Å MS and 2,6-lutidine in THF at 0 °C.

Cyanotetrazolylborohydride (CTB) anion-based ionic liquids with low viscosity and high energy capacity as ultrafast-igniting hypergolic fuels.

A series of hypergolic cyanotetrazolylborohydride (CTB) anion-based ionic liquids have been synthesized by a straightforward N-hydroboration of tetrazole followed by a salt metathesis reaction, which exhibited remarkably low viscosity (<20 mPa s), high density (often >1.1 g cm), and ultra-short ignition delay time (as short as 1.4 ms) upon contact with white fuming nitric acid (WFNA).

Pentazadiene: a high-nitrogen linkage in energetic materials.

A novel N-linear energetic moiety of pentazadiene has been constructed for the first time from a triazene precursor. Thus, a series of 1,3,5-tri(tetrazol-5-yl)pentaza-1,4-dienes have been synthesized in moderate to high yields by treatment of 1,3-bis(tetr-azol-5-yl)triazenes with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) under mild conditions. All compounds were fully characterized using IR spectroscopy, H and C NMR spectroscopy, HRMS, and differential scanning calorimetry (DSC), and, in the case of 1,3,5-tri(2-methyltetrazol-5-yl)pentaza-1,4-diene (2a) together with single crystal X-ray structuring and N NMR spectroscopy.

Highly Enantioselective α-Cyanation with 4-Acetylphenyl Cyanate.

A highly effective asymmetric version of α-cyanation of β-keto esters and amides was developed with a Lewis-acid catalyst. Thus, by using 10 mol % of a tridentate bisoxazoline-zinc(II) complex as the catalyst, a series of chiral nitriles containing a quaternary carbon center were obtained in excellent enantioselectivities (up to 97 % enantiomeric excess) and up to 95 % yield in the presence of 4 Å molar sieve at room temperature. For the first time, mild and active 4-acetylphenyl cyanate was used instead of cyano-hyperiodinate as the cationic cyano source for catalytic asymmetric α-cyanation.

The direct electrophilic cyanation of β-keto esters and amides with cyano benziodoxole.

The direct electrophilic α-cyanation of β-keto esters and amides has been developed using a hypervalent iodine benziodoxole-derived cyano reagent. The procedure is accomplished within 10 min and without the use of any catalyst in DMF, at room temperature. Thus, the highly functionalized quaternary carbon-centered nitriles were produced in high to excellent yields.

Epigallocatechin-3-gallate induces apoptosis, inhibits proliferation and decreases invasion of glioma cell.

Epigallocatechin-3-gallate (EGCG), a major polyphenol in green tea, has been considered a potential therapeutic and chemopreventive agent for cancer. Glioma is a malignant tumor with high mortality but effective therapy has not yet been developed. In this study, we found that EGCG induced apoptosis in U251 glioma cells via the laminin receptor (molecular weight 67 kDa) in a time- and dose-dependent manner, decreased their invasiveness and inhibited their proliferation.

7-Iodo-3,3-diphenyl-octa-hydro-benzo-furan.

The title compound, C20H21IO, was synthesized by cyclo-haloetherification of 2-(cyclo-hex-2-en-yl)-2,2-diphenyl-ethanol in CH2Cl2, and crystallized with two independent mol-ecules in the asymmetric unit. The six-membered cyclo-hexane ring adopts a chair conformation, while the five-membered ring adopts an envelope conformation with the fused C atom opposite the O atom as the flap in each case [displacements of the flap atoms = 0.6813 (3) and 0.

Asymmetric trifluoromethylation of aromatic aldehydes by cooperative catalysis with (IPr)CuF and quinidine-derived quaternary ammonium salt.

A general enantioselective trifluoromethylation of aldehydes has been developed using (IPr)CuF and quinidine-derived quaternary ammonium salt as the cooperative catalyst. Thus, a wide range of aromatic aldehydes have been converted to the corresponding products in up to 92% yield and 81% ee at 2 mol% of catalyst loading. The greatly enhanced activity and enantioselectivity result from the initiative generation of active [(IPr)CuCF(3)] as well as additional coordination activation of other copper species.

Synthesis and characterization of energetic 3-nitro-1,2,4-oxadiazoles.

All new: 3-Nitro-5-guanidino-1,2,4-oxadiazole (NOG) was synthesized from diaminoglycoluril with in situ generated dimethyldioxirane (DMDO). The impact sensitivity of NOG is more than 40 J with a decomposition temperature of 290 °C. Some other energetic derivatives have been prepared and characterized.