25 research outputs found
The 2017 Rohingya Influx into Bangladesh and Its Implications for the Host Communities
We addressed the research question, how does the host community perceive the effects of Rohingya influx to Bangladesh, from their perspectives using a questionnaire survey, key informant interviews, and focus group discussions. Bangladesh sheltered over a million Rohingyas, fleeing genocide and serious crimes against humanity, on humanitarian grounds. The local people welcomed them and offered direct support and assistance. Our findings suggest that their immediate sympathy for Rohingyas faded over time due to various factors. An overwhelming majority perceived the Rohingyas as pressure on their land and resources and being deprived on numerous grounds outweighed the disproportionate economic incentives of the influx. The findings offer fresh insights into the challenges of hosting refugees in the local communities because of the diverse impacts of forced displacemen
The Synthesis of cis- and trans-Fused Bicyclic Sugar Amino Acids
Four isomeric bicyclic sugar amino acids (SAAs) were prepared from an α-acetylenic-C-glucoside by employing a Petasis olefination and a ring-closing metathesis (RCM) as key steps. The applicability of the resulting SAAs in solid-phase peptide synthesis was demonstrated by the synthesis of a tetrapeptide
Synthesis of Pyranoid δ-Sugar Amino Acids and Their Oligomers from per-Benzylated β-C-Vinyl Glucoside.
ChemInform Abstract: Ring Expansion of 2-(α-Hydroxyalkyl)azetidines: A Synthetic Route to Functionalized Pyrrolidines.
Etude de la réactivité d'azétidines enantiomériquement pures
Nous avons étudié trois aspects de la réactivité d'azétidines énantiomériquement pures: après avoir adapté une extension de cycle décrite dans la littérature pour des pyrrolidines, l'étude des mécanismes réactionnels impliqués dans chacun de ces processus a mis en évidence la spécificité de la réactivité des azétidines. Puis nous avons étudié la capacité des sels d'azétidinium à se réarranger en des hétérocycles de plus grande taille sous l'action d'une base forte. Il a été discuté des facteurs contrôlant la sélectivité de ces réactions qui s'est toujours avérée excellente malgré la compétition permanente entre plusieurs voies réactionnelles possibles. Enfin, l'ouverture des sels d'azétidinium par des nucléophiles s'est révélée particulièrement régiosélective. La modélisation moléculaire a permis d'apporter des éléments de réponse à la sélectivité observée. L'ensemble de ces résultats a permis d'accroître les connaissances sur la réactivité des azétidines et d'envisager de nouvelles applications en synthèse organique.Three aspects of the reactivity of enantiopure azetidines have been studied. We first adopted the ring expansion reaction described in the literature for pyrrolidines, and studied the mechanisms involved in these enlargement reactions, which put in light the specifie reactivity of azetidines. We next studied the ability of azetidinium salts to rearrange to heterocycles of larger size under strong basic conditions. Parameters goveming the selectivity of these reactions were excellent in aH cases even though several pathways were possible, are discussed. Ring opening reactions of azetidinium salts by different nucleophiles showed excellent regioselectivity. Ca1culations allowed for a rationalisation of experimental results. The work discussed in this dissertation permitted to improve knowledge about azetidines reactivity and should allow for new applications in organic chemistryVERSAILLES-BU Sciences et IUT (786462101) / SudocSudocFranceF
Reinvestigation of the Synthesis of Per-benzylated Glycosylethenes: A New Result
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