Catalytic liquid- and gas-phase oxidations for the synthesis of intermediates and specialty chemicals: some examples of industrial relevance

Nowadays, it is clear that the target of creating a sustainable future for the next generations requires to re-think the industrial application of chemistry. It is also evident that more sustainable chemical processes may be economically convenient, in comparison with the conventional ones, because fewer by-products means lower costs for raw materials, for separation and for disposal treatments; but also it implies an increase of productivity and, as a consequence, smaller reactors can be used. In addition, an indirect gain could derive from the better public image of the company, marketing sustainable products or processes. In this context, oxidation reactions play a major role, being the tool for the production of huge quantities of chemical intermediates and specialties. Potentially, the impact of these productions on the environment could have been much worse than it is, if a continuous efforts hadn’t been spent to improve the technologies employed. Substantial technological innovations have driven the development of new catalytic systems, the improvement of reactions and process technologies, contributing to move the chemical industry in the direction of a more sustainable and ecological approach. The roadmap for the application of these concepts includes new synthetic strategies, alternative reactants, catalysts heterogenisation and innovative reactor configurations and process design. Actually, in order to implement all these ideas into real projects, the development of more efficient reactions is one primary target. Yield, selectivity and space-time yield are the right metrics for evaluating the reaction efficiency. In the case of catalytic selective oxidation, the control of selectivity has always been the principal issue, because the formation of total oxidation products (carbon oxides) is thermodynamically more favoured than the formation of the desired, partially oxidized compound. As a matter of fact, only in few oxidation reactions a total, or close to total, conversion is achieved, and usually the selectivity is limited by the formation of by-products or co-products, that often implies unfavourable process economics; moreover, sometimes the cost of the oxidant further penalizes the process. During my PhD work, I have investigated four reactions that are emblematic of the new approaches used in the chemical industry. In the Part A of my thesis, a new process aimed at a more sustainable production of menadione (vitamin K3) is described. The “greener” approach includes the use of hydrogen peroxide in place of chromate (from a stoichiometric oxidation to a catalytic oxidation), also avoiding the production of dangerous waste. Moreover, I have studied the possibility of using an heterogeneous catalytic system, able to efficiently activate hydrogen peroxide. Indeed, the overall process would be carried out in two different steps: the first is the methylation of 1-naphthol with methanol to yield 2-methyl-1-naphthol, the second one is the oxidation of the latter compound to menadione. The catalyst for this latter step, the reaction object of my investigation, consists of Nb2O5-SiO2 prepared with the sol-gel technique. The catalytic tests were first carried out under conditions that simulate the in-situ generation of hydrogen peroxide, that means using a low concentration of the oxidant. Then, experiments were carried out using higher hydrogen peroxide concentration. The study of the reaction mechanism was fundamental to get indications about the best operative conditions, and improve the selectivity to menadione. In the Part B, I explored the direct oxidation of benzene to phenol with hydrogen peroxide. The industrial process for phenol is the oxidation of cumene with oxygen, that also co-produces acetone. This can be considered a case of how economics could drive the sustainability issue; in fact, the new process allowing to obtain directly phenol, besides avoiding the co-production of acetone (a burden for phenol, because the market requirements for the two products are quite different), might be economically convenient with respect to the conventional process, if a high selectivity to phenol were obtained. Titanium silicalite-1 (TS-1) is the catalyst chosen for this reaction. Comparing the reactivity results obtained with some TS-1 samples having different chemical-physical properties, and analyzing in detail the effect of the more important reaction parameters, we could formulate some hypothesis concerning the reaction network and mechanism. Part C of my thesis deals with the hydroxylation of phenol to hydroquinone and catechol. This reaction is already industrially applied but, for economical reason, an improvement of the selectivity to the para di-hydroxilated compound and a decrease of the selectivity to the ortho isomer would be desirable. Also in this case, the catalyst used was the TS-1. The aim of my research was to find out a method to control the selectivity ratio between the two isomers, and finally to make the industrial process more flexible, in order to adapt the process performance in function of fluctuations of the market requirements. The reaction was carried out in both a batch stirred reactor and in a re-circulating fixed-bed reactor. In the first system, the effect of various reaction parameters on catalytic behaviour was investigated: type of solvent or co-solvent, and particle size. With the second reactor type, I investigated the possibility to use a continuous system, and the catalyst shaped in extrudates (instead of powder), in order to avoid the catalyst filtration step. Finally, part D deals with the study of a new process for the valorisation of glycerol, by means of transformation into valuable chemicals. This molecule is nowadays produced in big amount, being a co-product in biodiesel synthesis; therefore, it is considered a raw material from renewable resources (a bio-platform molecule). Initially, we tested the oxidation of glycerol in the liquid-phase, with hydrogen peroxide and TS-1. However, results achieved were not satisfactory. Then we investigated the gas-phase transformation of glycerol into acrylic acid, with the intermediate formation of acrolein; the latter can be obtained by dehydration of glycerol, and then can be oxidized into acrylic acid. Actually, the oxidation step from acrolein to acrylic acid is already optimized at an industrial level; therefore, we decided to investigate in depth the first step of the process. I studied the reactivity of heterogeneous acid catalysts based on sulphated zirconia. Tests were carried out both in aerobic and anaerobic conditions, in order to investigate the effect of oxygen on the catalyst deactivation rate (one main problem usually met in glycerol dehydration). Finally, I studied the reactivity of bifunctional systems, made of Keggin-type polyoxometalates, either alone or supported over sulphated zirconia, in this way combining the acid functionality (necessary for the dehydrative step) with the redox one (necessary for the oxidative step). In conclusion, during my PhD work I investigated reactions that apply the “green chemistry” rules and strategies; in particular, I studied new greener approaches for the synthesis of chemicals (Part A and Part B), the optimisation of reaction parameters to make the oxidation process more flexible (Part C), and the use of a bioplatform molecule for the synthesis of a chemical intermediate (Part D).

Histone deacetylase inhibitors in adult patients with diffuse large b-cell lymphoma relapsed/refractory: a phase II study with Panobinostat

Backgrounds:Treatment of patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) not eligible to high dose therapy represents an unmet medical need. Panobinostat showed encouraging therapeutic activity in studies conducted in lymphoma cell lines and in vivo in patients with advanced hematologic malignancies.Purpose:FIL-PanAL10 (NCT01523834) is a phase II, prospective multicenter trial of the Fondazione Italiana Linfomi (FIL) to evaluate safety and efficacy of single agent Panobinostat as salvage therapy for R/R DLBCL patients and to evaluate a possible relationships between response and any biological features. Patients and Methods:Patients with R/R DLBCL were included. The treatment plan included 6 induction courses with Panobinostat monotherapy followed by other 6 courses of consolidation. The primary objective was to evaluate Panobinostat activity in terms of overall response (OR); secondary objectives were: CR rate, time to response (TTR), progression-free survival (PFS), safety and feasibility of Panobinostat. We included evaluation of the impact of pharmacogenetics, immunohistochemical patterns and patient’s specific gene expression and mutations as potential predictors of response to Panobinostat as explorative objectives. To this aim a pre-enrollment new tissue biopsy was mandatory. ResultsThirty-five patients, 21 males (60%), were enrolled between June 2011 and March 2014. At the end of induction phase, 7 responses (20%) were observed, including 4 CR (11%), while 28 patients (80%) discontinued treatment due to progressive disease (PD) in 21 (60%) or adverse events in 7 (20%). Median TTR in 9 responders was 2.6 months (range 1.8-12). With a median follow up of 6 months (range 1-34), the estimated 12 months PFS and OS were 27% and 30.5%, respectively. Grade 3-4 thrombocytopenia and neutropenia were the most common toxicities (in 29 (83%) and 12 (34%) patients, respectively. Conclusions The results of this study indicate that Panobinostat might be remarkably active in some patients with R/R DLBCL, showing durable CR

Fibrinolysis Versus Primary Pci In Stemi Patients Enrolled In The International Survey Of Acute Coronary Syndromes In Transitional Countries

Primary angioplasty has been shown to be more effective than fibrinolysis in terms of mortality and adverse outcomes. More recent data, however, suggests that timely reperfusion with fibrinolysis is comparable to primary angioplasty. The current study gathered data from the International Survey of Acute Coronary Syndromes in Transitional Countries registry. Among 7406 ST-elevation myocardial infarction patients presenting within 12 hours from symptom onset, 6315 underwent primary percutaneous coronary intervention and 1091 were treated with fibrinolysis. The primary outcome was 30-day mortality, while the secondary outcome was a composite of 30-day incidence of death, severe left ventricular dysfunction, stroke or reinfarction. Patients who underwent primary angioplasty tended to have a greater cardiovascular risk profile and were slightly older. On the other hand, patients treated with fibrinolysis received less anti-platelet medications yet were more often prescribed beta blockers in the acute phase. Among those who received fibrinolysis, 43% underwent coronary angiography while 32.3% were treated with a subsequent angioplasty. Total ischemic time was lower in patients undergoing fibrinolysis (185 minutes) than in those treated with primary angioplasty (258 minutes). Rates of primary and secondary combined endpoints were higher in patients receiving fibrinolysis compared to those receiving primary angioplasty (7.8% vs. 4.1%; p<0.0001; OR 1.97, 95% CI, 1.38-2.81; and 14.8% vs. 10.1%, p<0.0001; OR 1.43, 95% CI, 1.12-1.81). When considering only patients receiving reperfusion within 3 hours, regardless of reperfusion strategy, differences in mortality (6.3% vs. 4%, p=0.094, for fibrinolysis or primary angioplasty, respectively; OR 0.87, 95% CI, 0.35-2.16) and in the combined secondary endpoint were no longer observed (12.9% vs 10.8%, p=0.33; OR 0.98, 95% CI, 0.58-1.64), and female sex was no longer a significant predictor of adverse outcomes. When performed 3 hours from symptom onset, fibrinolysis is safe and feasible, in terms of mortality and adverse outcomes, compared to primary angioplasty.

Environmental assessment of industrial chemical and primary sector processes from a life cycle perspective

During the PhD program in chemistry at the University of Bologna, the environmental sustainability of some industrial processes was studied through the application of the LCA methodology. The efforts were focused on the study of processes under development, in order to assess their environmental impacts to guide their transfer on an industrial scale. Processes that could meet the principles of Green Chemistry have been selected and their environmental benefits have been evaluated through a holistic approach. The use of renewable sources was assessed through the study of terephthalic acid production from biomass (which showed that only the use of waste can provide an environmental benefit) and a new process for biogas upgrading (whose potential is to act as a carbon capture technology). Furthermore, the basis for the development of a new methodology for the prediction of the environmental impact of ionic liquids has been laid. It has already shown good qualities in identifying impact trends, but further research on it is needed to obtain a more reliable and usable model. In the context of sustainable development that will not only be sector-specific, the environmental performance of some processes linked to the primary production sector has also been evaluated. The impacts of some organic farming practices in the wine production were analysed, the use of the Cereal Unit parameter was proposed as a functional unit for the comparison of different crop rotations, and the carbon footprint of school canteen meals was calculated. The results of the analyses confirm that sustainability in the industrial production sector should be assessed from a life cycle perspective, in order to consider all the flows involved during the different phases. In particular, it is necessary that environmental assessments adopt a cradle-to-gate approach, to avoid shifting the environmental burden from one phase to another.

A phase II, single arm study of CarbopLatin plus Etoposide with Bevacizumab and Atezolizumab in patients with exTEnded-disease small-cell lung cancer (SCLC) – CeLEBrATE trial

Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumor diagnosed at extended disease SCLC (ES-SCLC) stage in about 70% of cases. The new standard of treatment for patients with ES-SCLC is a combination of platinum-etoposide chemotherapy and atezolizumab or durvalumab, two programmed cell death ligand 1 (PD-L1) inhibitory monoclonal antibodies (mAb). However, the benefit derived from the addition of PD-L1 inhibitors to chemotherapy in ES-SCLC was limited and restricted to a subset of patients. The vascular endothelial growth factor (VEGF) is the most important pro-angiogenic factor implicated in cancer angiogenesis, which is abundant in SCLC and associated with poor prognosis. Antiangiogenic agents, such as bevacizumab, a humanized mAb against VEGF, added to platinum-etoposide chemotherapy improved progression-free survival in SCLC in two trials, but it did not translate into a benefit in overall survival. Nevertheless, VEGF has also acts as a mediator of an immunosuppressive microenvironment and its inhibition can revert the immune-suppressive tumor microenvironment and potentially enhance the efficacy of immunotherapies. Based on available preclinical data, we hypothesized that VEGF inhibition by bevacizumab could improve atezolizumab efficacy in a synergistic way and designed a phase II single-arm trial of bevacizumab in combination with carboplatin, etoposide, and atezolizumab as first-line treatment in ES-SCLC. The trial, which is still ongoing, enrolled 53 patients, including those with treated or untreated asymptomatic brain metastases (provided criteria are met), who received atezolizumab, bevacizumab, carboplatin and etoposide for 4-6 cycles (induction phase), followed by maintenance with atezolizumab and bevacizumab for a maximum of 18 total cycles or until disease progression, patient refusal, unacceptable toxicity. The evaluation of efficacy of the experimental combination in terms of 1-year overall survival rate is not yet mature (primary objective of the trial). The combination was feasible and the toxicity profile manageable (secondary objective of the trial).