Chunxu Lu

Nitration of Simple Aromatics with NO2 under Air Atmosphere in the Presence of Novel Brønsted Acidic Ionic Liquids

Abstract Aromatics nitrate with NO2/air catalyzed by novel Brønsted acidic ionic liquids (ILs) without any volatile chlorinated organic solvent under mild conditions. The ILs employed were caprolactam based, [Caprolactam]X (X−=pTSO−, BSO−, BF4 −, NO3 −), which are of relatively lower cost and lower toxicity than traditional imidazolium‐based ILs. The nitration reactions were carried out at −15 to −0°C first, then at room temperature for a longer time with a little excessive NO2 (ca. 1.4 eqv.) for moderate yield (for toluene). The IL could be reused four times.

Compounds based on 3-amino-4-(5-methyl-1,2,4-oxadiazol-3-yl)furazan as insensitive energetic materials

3-Amino-4-(5-methyl-1,2,4-oxadiazol-3-yl)furazan was synthesized by reacting 4-amino-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide with acetamide at a high temperature of 180 °C. N-Trinitroethylamino derivatives and energetic salts based on 3-amino-4-(5-methyl-1,2,4-oxadiazol-3-yl)furazan, which is a combination of 1,2,5- and 1,2,4-oxadizaole rings, were synthesized and fully characterized by multinuclear NMR spectroscopy, IR, and elemental analysis. And, the structures of compounds 1, 3, 4, 7, 9 were further confirmed by single crystal X-ray diffraction. The thermal stabilities of 1–12 were determined by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC), indicating that the reported compounds have moderate thermal stabilities (172–246 °C, except for 3 159 °C). Compounds 1, 4–12 are insensitive towards impact (≥40.1 J) and friction (≥360 N) which were measured by standardized impact and friction tests. Detonation performance was obtained based on the calculated heats of formation and measured densities which indicated that most of these materials are superior to TNT.

An interesting ring cleavage of a 1,2,4-oxadiazole ring

Herein, the mono-trinitroethyl-substituted product of 3,5-diamino-1,2,4-oxadiazole (1) was easily obtained. However, the bis(trinitroethyl)- or nitramino-substituted product of 1 in the presence of acid was not obtained, as expected, due to an interesting ring cleavage of the 1,2,4-oxadiazole ring. Compound 1 and the ring cleavage products 2 and 3 exhibit good energetic performance and acceptable sensitivities.

Regioselective Ring Opening of Styrene Oxide Catalyzed by MoO2(acac)2

Abstract The ring-opening reaction of styrene oxide with various nitrogen, oxygen, and carbon nucleophiles catalyzed by MoO2(acac)2 was described. The corresponding ring-opening compounds with nearly 100% regioselectivities were obtained under mild conditions in moderate to good yields. MoO2(acac)2 is a highly efficient catalyst for the ring opening of styrene oxide. The reaction serves as a simple and efficient method for the synthesis of 1,2-bifunctional compounds. GRAPHICAL ABSTRACT