Imines, carbon-nitrogen double bonds, are fundamentally important functional groups in organic chemistry. This is largely due to the fact that imines act as electrophiles in C–C bond forming reactions towards carbon nucleophiles, thereby serving one of the most widely used precursors for the formation of amines in both synthetic and biosynthetic settings.1–5 If the carbon atom of the imine could be rendered electron-rich, the imine could react as a nucleophile instead of as an electrophile. Such a reversal in the electronic characteristics of the imine functionality would facilitate the development of new chemical transformations that convert imines into amines via C–C bond forming reactions with carbon electrophiles, thereby creating new opportunities for the efficient synthesis of amines. The development of asymmetric ‘umpolung’ reactions of imines remains an uncharted ground, in spite of the far-reaching impact of such reactions in organic synthesis. Here we report the discovery and development of new chiral phase transfer catalysts that promote the highly efficient asymmetric umpolung reactions of imines and enals. These catalysts mediate the deprotonation of imines and direct the 2-azaallylanions thus formed to react in a highly chemoselective, regioselective, diastereoselective and enantioselective fashion with enals. The reaction tolerates a broad range of imines and enals, and can be carried out in high yield with as little as 0.01 mol % catalyst with a moisture and air-tolerant operational protocol. These umpolung reactions provide a conceptually new and practical approach towards chiral amino compounds.

Mallory-type photocyclization involves a series of photoreactions of stilbenes, o-terphenyls and related derivatives, which undergo intramolecular cyclization via dihydrophenanthrene intermediates. In typical Mallory photocyclizations, oxidants are usually needed to produce the final phenanthrene-containing product. In the research described here, appropriately fluorinated stilbenes and o-terphenyls undergo ring closure and HF is eliminated. This photocyclodehydrofluorination (PCDHF) reaction is very useful to produce a wide range of selectively fluorinated polynuclear aromatic hydrocarbons that possess a phenanthrene (or heterocyclic analogue of phenanthrene) substructure. These fluorinated products are of great interest in various aspects of the materials science.

Our results suggested that unilateral PKP was a safe and reliable treatment for OVCFs with IVC. However, the IVC group had higher incidence of bone cement leakage during surgery and more severe KA rebound during the follow-up period. Therefore, to reduce the incidence of bone cement leakage, it is very important to evaluate the pre-operative imaging and inject the cement carefully and repetitiously. When cement leakages are found, injection should be stopped immediately. Longer rehabilitation interventions such as wearing suitable brace, doing exercise to strengthen low-back muscle, and replacing bending with squatting in ordinary living are essential to prevent KA rebound in patients with OVCFs with IVC. However, extended follow-up may be necessary for patients with OVCFs with IVC.

Objective Osteoporotic thoraco‐lumbar burst fractures with serious pain are very common, and the optimal treatment of burst fractures without any neurological deficits has not yet been properly codified. The objective of this study was to evaluate prospectively the clinical effects and pain relief of unilateral percutaneous kyphoplasty (PKP) on osteoporotic thoraco‐lumbar burst fractures. Methods Forty‐six patients with osteoporotic thoraco‐lumbar burst fractures were treated by PKP in our hospital from January 2016 to January 2017. The height of posterior wall (HPW), the height of anterior wall (HAW) and kyphotic angle (KA) were measured via x‐ray radiographs before surgery, one day after surgery and at final follow‐up. Visual analogue scale (VAS) score and the oswestry disability index (ODI) score were evaluated preoperatively, postoperatively and at final follow‐up. All the patients with osteoporotic thoraco‐lumbar burst fractures were treated by unilateral PKP. Radiological evaluation (anteroposterior and lateral x‐ray radiographs and CT) was performed. Results All patients were followed‐up, and the mean follow‐up was 28.8 ± 7.0 months. The preoperative HAW was 20.1 ± 2.3 mm, and the HAW was significantly improved to 22.9 ± 2.4 mm after operation (p < .05), and at the final follow‐up, the HAW was 19.9 ± 2.1 mm, which was lower than the postoperative HAW. The HPW was also significantly corrected after surgery (p < .05). There were no significant differences between postoperative HPW and HPW at the final follow‐up (p > .05). The KA was significantly corrected after operation (p < .05), but relapse occurred at the final follow‐up, and at the final follow‐up, the average of KA was 19.4 ± 1.6 degree. The VAS and ODI were significantly improved at the final follow‐up compared to the preoperative period (p < .05). Cement leakage was found in eight patients, and adjacent vertebral fracture (VF) was found in two patients. Conclusions Our results showed that unilateral PKP acquired satisfactory treatment effect and pain relief in the management of osteoporotic thoraco‐lumbar burst fractures. Meticulous evaluation of preoperative images and careful repetitious injection of cement are important to prevent cement leakage. Significance Our present results showed that unilateral PKP was an effective method to obtain satisfactory pain relief in the management of osteoporotic thoraco‐lumbar burst fractures. It may a good indication for the patients with osteoporotic thoraco‐lumbar burst fractures, and the patients could not tolerate the serious acute pain by conservative treatment.