A convergent approach to the forskolin skeleton is described. Assembly of a simplified tricyclic framework is achieved in a single step via the dihydropyrone Diels–Alder reaction. Selective manipulation of the resulting cycloadduct, in conjunction with an unusual equilibration of the C8 stereocenter, provides access to scaffolds that differ in relative stereochemistry at both the A/B and B/C ring junctions.
The catalytic intermolecular cyclization of thiophenols with allylic alcohols in the presence of bismuth triflate afforded the corresponding thiochromane derivatives in a one-pot reaction. The Bi(OTf)3-catalyzed reaction was also applied to the intermolecular cyclization of diaryl disulfides with 3-methylbut-2-en-1-ol to produce the corresponding thiochromanes.
Hydrazine and its derivatives have served as a conventional bipropellant fuel for several decades. However, their extremely acute toxicity and carcinogenicity, high volatility, and environmental impact have attracted significant attention. In order to synthesize green bipropellant fuels with high density, high specific impulse, and good thermal stability, three novel N-alkyl-1,2,4-triazole–borane complexes were successfully synthesized by reacting alkylated 1,2,4-triazole coordinated with sodium borohydride in the presence of ammonium sulfate. During the droplet test with white fuming nitric acid, there was a relatively short ignition delay time of 98 ms. Additionally, these hypergolic fuels possessed a high density exceeding 1.10 g cm–3, and the specific impulse is ranging from 187 to 199 s, and the highest decomposition temperature reaches 153.4 °C. These results demonstrate their great potential as hypergolic fuels or hypergolic ionic liquid additives in the field of hypergolic materials.
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：