Philippe Gonzalez

Functionalized Chitosan as a Green, Recyclable, Biopolymer-Supported Catalyst for the 3+2 Huisgen Cycloaddition

Owing to increasing concern about environmental impact, tremendous effort has been made towards the development of new processes that minimize pollution in chemical synthesis. For this reason and others (catalyst removal, recovery, and recycling), heterogeneous catalysis is clearly on the rise, including in industry. Of the many systems that have been developed over the past decades, metallic species supported on inorganic materials (e.g. SiO2, Al2O3) or on charcoal are the most common. The immobilization of transition metals on polymer supports derived from petrochemicals (e.g. polystyrenes) has also been the focus of many efforts. Recent developments for cleaner, sustainable chemistry are being driven by a shift from petrochemical-based feedstocks to biological materials. There is considerable interest in exploiting natural polymer macrostructures, and in particular those of polysaccharides, to create high-performance and environmentally friendly catalysts. Indeed, polysaccharides present many advantages that may stimulate their use as polymeric supports for catalysis: 1) They are present in enormous quantity on earth, 2) they contain many functionalities that can be used readily for the anchoring of organometallic species, 3) they contain many stereogenic centers, and 4) they are chemically stable but biodegradable. Surprisingly, although there has been a worldwide realization that nature-derived polysaccharides can provide the raw materials needed for the production of numerous industrial consumer goods, their use as supports for catalysis is still in its infancy. Chitosan (Figure 1 A) is a particularly attractive polysaccharide for application in catalysis owing to the presence of readily functionalizable amino groups and its insolubility in organic solvents. A copolymer of b(1!4)-2-amino-2-deoxyd-glucopyranose and 2-acetamido-2-deoxy-d-glucopyranose, chitosan results from incomplete deacetylation of chitin. At least 10 gigatons of chitin are constantly present in the biosphere; thus, chitosan is a renewable green material. Of

Opening The Fortress. The Work of Public Gaze on the Swiss Asylum Reality

The Fortress (La Forteresse) is a 2008 documentary film by Fernand Melgar that reports the Swiss asylum reality from a distant but committed point of view. The documentary describes the life of asylum seekers awaiting in a federal centre the decision to grant them—or not—refugee status. It subtly raises the issue of the role that “textual realities”, grasped from the spectators point of view, play in the production of public discourses. Most of all, it subtly poses the question of the (Swiss) spectator as an actor of the asylum policy, in the context of a semi-direct democracy. After evoking the notion of sensible experience for linking spectatorship to politics, we look at how the documentary invites its model spectator to accept the films moral premises. Furthermore, focusing on the Swiss public sphere, we deliver an account of the reception by empirical spectators, notably by a group of leftist activists that tend to subvert Melgars intentions. This two-fold analysis leads us to exhibit that, in a context of discursive struggles, The Fortress generates an original space of deliberation and experience, which appeals to the public to exercise their political agency on asylum policy without being constricted by an antagonist framework.