A New Sustainable Multistep Catalytic Process from Benzene to Caprolactam: Amination, Hydroximation and Beckmann Rearrangement Promoted and Catalyzed by Trifluoroacetic Acid.

Here we report some results on a 3 steps benzene caprolactam process via amination, aniline Hydroxymation and Beckmann rearrangement. The amination proceeds with hydroxylamine trifluoroacetate, with 97% of conversion and selectivity of 90%, catalyzed by V compounds. We achieve 98% of conversion and 95% of selectivity in the hydroxymation of aniline in the presence of hydroxylamine trifluoroacetate, sulfonic resin and Pd/C. While in the absence of the resin, hydrogenation of hydroxylamine trifluoroacetate occurs readily to the ammonium salt. The reaction occurs likely by the exchanged hydroxylamine and the aniline reduction intermediate. The use of hydroxylamine trifluoroacetate, instead of the chloride, favors the sustainability of the process by avoiding the ammonium chloride formation. The absence of salt except those derived from the trifluoroacetic acid allows a complete reuse of the trifluoroacetic acid and the only byproduct is ammonium nitrate obtained by resin regeneration. Beckmann rearrangement of the so produced cyclohexanone oxime occurs easily after diethyl ether evaporation and additions of a solution trifluoroacetic acid acetonitrile in high yield and selectivity. Graphical Abstract: New three steps caprolactam process via benzene amination and aniline hydrogenation. Supplementary Information: The online version contains supplementary material available at 10.1007/s10562-022-04207-9.

Brazilian FRED Registry: A Prospective Multicenter Study for Brain Aneurysm Treatment-The BRED Study.

BACKGROUND AND PURPOSE: The development of flow diverters has changed the endovascular approach to intracranial aneurysms. On the basis of good results, the indications for flow diverters have expanded to include aneurysms of different shapes, locations, and sizes. The objective of the study was to report on the performance of the Flow Re-Direction Endoluminal Device (FRED) in intracranial aneurysm treatment at early and medium-term follow-up. MATERIALS AND METHODS: This single-arm, multicentric, prospective, observational study assessed aneurysm treatment with the FRED. The primary outcome was complete aneurysm occlusion at 6 and 12 months, and the secondary outcome was to evaluate the safety of the FRED with respect to stroke and death rates. RESULTS: Between June 2016 and August 2018, a total of 100 consecutive patients with 131 aneurysms were treated in 107 procedures. Total occlusion rates were 91% and 95% at 6 and 12 months. There was 1 death, and the total final morbidity rate was 1.8%. The complication rate was 4.6%. CONCLUSIONS: As reported previously, the FRED has proved to be a safe and effective tool, with high occlusion rates. The design of the stent makes it more difficult to perform balloon angioplasty compared with similar devices. A branch arising from the aneurysm sac was found to be a predictor of nonocclusion at 12 months, though larger series are needed to estimate the magnitude of the association.

Copper molybdate synthesized by sonochemistry route at room temperature as an efficient solid catalyst for esterification of oleic acid.

Copper molybdate nanoplates were synthesized by a sonochemical process at room temperature, which we report as a simple and cost-effective route. Structural analysis of the material by the Rietveld method of X-ray diffraction (XRD) data revealed lindgrenite Cu3(MoO4)2(OH)2 in a single-phase structure. All the vibrational modes characteristic of the space group were identified by Raman vibrational and near-infrared (NIR) spectroscopies. The profile obtained for N2 adsorption/desorption was type III hysteresis, characteristic of mesoporous materials, with a surface area of 70.77(1) m2 g-1. The micrographs of the material obtained by scanning electron microscopy showed nanoplates with nanometric sizes and an anisotropic growth aspect. The catalytic activity of lindgrenite was evaluated by esterifying oleic acid with methanol, showing high conversion rate to methyl oleate and good catalyst stability after seven recycling cycles. Above all, the best catalytic performance was reached when we optimized parameters such as oleic acid:methanol molar ratio of 1:5, 5% of catalyst dosage, and reaction time of 5 h, resulting in 98.38% of conversion at 413 K. Therefore, sonochemically synthesized lindgrenite proved to be a high potential material for biofuel production by oleic acid esterification.

Basilar Artery Fenestration Aneurysms: Endovascular Treatment Strategies Based on 3D Morphology.

PURPOSE: Basilar artery is the second most common site of fenestration, after the anterior communicating region. It is believed this variation predisposes a patient to posterior aneurysm formation and increases the complexity of the surgical anatomy. Endovascular management has become the first option to treat these aneurysms. We retrospectively evaluated eight patients, who underwent endovascular treatment for fenestrated basilar artery related aneurysms (fBA-AN). Additionally, based on our findings and on literature review, we developed a treatment strategy based on a proposed classification of fBA-AN. METHODS: Between June 2010 and September 2012, eight patients harboring nine basilar artery fenestration aneurysms were consecutively treated. Based on aneurysm morphology (neck size) and its relationship to the fenestration (sparing or not one channel) characterized by 3D-DSA, we proposed a simple classification and treatment strategies. Additionally, a literature review was performed. RESULTS: All patients received endovascular treatment. Most aneurysms involved the vertebrobasilar junction and both channels of the fenestration. A total of 5 aneurysms had wide neck while 4 had narrow neck. Overall, 5 (55.5 %) aneurysms were treated with stent assisted coiling, 3 (33.3 %) aneurysms with selective coiling, and 1 (11.1 %) aneurysm with balloon assisted coiling. We had only 1 (11.1 %) complication, named aneurysm rupture. CONCLUSION: Basilar artery fenestration aneurysms are rare and complex lesions. Endovascular treatment appears to be safe and efficient. The detailed understanding of the aneurysm morphology and its relation to the fenestration is strongly recommended to treatment planning. Further studies are necessary to validate the utility of the proposed classification and treatment strategy.

Endovascular treatment of isolated posterior inferior cerebellar artery dissecting aneurysms: parent artery occlusion or selective coiling?

PURPOSE: Isolated posterior inferior cerebellar artery dissecting aneurysms are rare lesions. Their underlying pathology, presentation, and natural history are poorly understood. Their treatment is controversial, and few data are available regarding the best treatment. We conducted the first study comparing selective coiling and parent artery occlusion for the treatment of isolated PICA dissecting aneurysms. METHODS: All patients harboring isolated PICA dissecting aneurysms treated between January 2006 and October 2012, in a single center, were retrospectively evaluated. Patients were consecutively submitted either to selective coiling or parent artery occlusion. The safety and durability (recanalization and rebleeding rates) of each treatment were established. In order to compare the results of both treatment modalities, we also performed a literature search of all cases of isolated PICA dissecting aneurysms endovascularly treated. RESULTS: Fourteen patients harboring isolated PICA dissecting aneurysms were assigned to endovascular treatment in our center (eight to selective coiling vs six to parent artery occlusion). There was no statistical difference between both groups regarding complications. No patient experienced rebleeding. One recanalization was observed in the selective coiling group. Based on literature review (83 cases), selective coiling and parent artery occlusion showed similar success rate in preventing rebleeding. Parent artery occlusion was significantly associated with a higher risk of ischemic complication (p = 0.013). CONCLUSIONS: Both selective coiling and parent artery occlusion are highly effective in preventing rebleeding in isolated PICA dissecting aneurysms. Although total complication rate is similar between both modalities, parent artery occlusion is significantly associated to a higher risk of ischemic events.

Direct vertebral artery access for the endovascular treatment of basilar artery aneurysms.

The femoral approach has been considered the preferred technique for the endovascular treatment of intracranial aneurysms. Occasionally, aneurysms are not amenable to the standard femoral approach. We describe four cases of basilar artery aneurysm that were treated by the direct vertebral artery access of V1 at the cervical region. The direct vertebral artery access technique can provide an alternative route in selected cases for the treatment of basilar artery aneurysms.