5 research outputs found

    A Modified Galam's Model

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    In this paper we analyze the stochastic model proposed by Galam in [2], for information spreading in a `word-of-mouth' process among agents, based on a majority rule. Using the communications rules among agents defined in [2], we first perform simulations of the `word-of-mouth' process and compare the results with the theoretical values predicted by Galam's model. Since some dissimilarities arise in particular when a small number of agents is considered, we suggest some enhancements by introducing a new parameter dependent model. We propose a modified Galam's scheme which is asymptotically coincident with the original model in [2]. Furthermore, for relatively small values of the parameter, we provide a numerical experience proving that the modified model often outperforms the original one, in terms of efficiency.Word-of-mouth process, information spreading, agent based simulation

    Metal-free photocatalytic cross-electrophile coupling enables C1 homologation and alkylation of carboxylic acids with aldehydes

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    Authors are grateful to have received generous funding from the European Union H2020 research and innovation program under the Marie S. Curie Grant Agreement (PhotoReAct, No 956324, S.B., M.L., A.L., G.M., E.Z.C., T.N.; CHAIR, No 860762, A.P., M.J., T.N.)In contemporary drug discovery, enhancing the sp3-hybridized character of molecular structures is paramount, necessitating innovative synthetic methods. Herein, we introduce a deoxygenative cross-electrophile coupling technique that pairs easily accessible carboxylic acid-derived redox-active esters with aldehyde sulfonyl hydrazones, employing Eosin Y as an organophotocatalyst under visible light irradiation. This approach serves as a versatile, metal-free C(sp3)−C(sp3) cross-coupling platform. We demonstrate its synthetic value as a safer, broadly applicable C1 homologation of carboxylic acids, offering an alternative to the traditional Arndt-Eistert reaction. Additionally, our method provides direct access to cyclic and acyclic β-arylethylamines using diverse aldehyde-derived sulfonyl hydrazones. Notably, the methodology proves to be compatible with the late-stage functionalization of peptides on solid-phase, streamlining the modification of intricate peptides without the need for exhaustive de-novo synthesis.Peer reviewe

    Stochastic model of agent interaction with opinion leaders

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    We analyze the problem of agents' interactions in a given population. The purpose of this paper is twofold. Starting from a scheme proposed by Galam [ Physica A 320 571 (2003)], which is based on a majority rule to treat the individuals’ interactions, we first study some of its relevant properties. Then, we introduce special individuals, called opinion leaders, who play a key role in information spreading in several practical applications. Opinion leaders have the special feature of strongly interfering with the process based on the majority rule, speeding up the diffusion. We consider a model describing agents’ interactions, which encompasses Galam's proposal, where opinion leaders are included as special agents. Then we study its specific properties which significantly recast and extend some conclusions drawn for the models given by Galam and Ellero, Fasano, and Sorato [ Physica A 388 3901 (2009)]. Finally, we provide theoretical and numerical results concerning the dynamics of our model, showing that a small percentage of opinion leaders may both accelerate and/or even reverse the overall consensus among all the agents

    Photocatalytic Deoxygenative Alkylation of C(sp3)−H Bonds Using Sulfonylhydrazones

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    The ability to construct C(sp3)–C(sp3) bonds from easily accessible reagents is a crucial, yet challenging endeavor for synthetic organic chemists. Herein, we report the realization of such a cross-coupling reaction, which combines N-sulfonyl hydrazones and C(sp3)–H donors through a diarylketone-enabled photocatalytic Hydrogen Atom Transfer and a subsequent fragmentation of the obtained alkylated hydrazide. This mild and metal-free protocol was employed to prepare a wide array of alkyl-alkyl cross-coupled products and is tolerant of a variety of functional groups. The application of this chemistry further provides a preparatively useful route to various medicinally-relevant compounds, such as homobenzylic ethers, aryl ethyl amines, β-amino acids and other moieties which are commonly encountered in approved pharmaceuticals, agrochemicals and natural products

    Accelerated D‑Fructose acid-catalyzed reactions in thin films formed by charged microdroplets deposition

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    Thin films derived by the deposition of charged microdroplets generated in the ESI source of a mass spectrometer act as highly concentrated reaction vessels in which the final products of an ion−molecule reaction can be isolated by their precipitation onto a solid surface under ambient conditions. In this study, the ESI Z-spray source supplied to a Q-TOF Ultima mass spectrometer was used to investigate the D fructose acid-catalyzed reactions by microdroplets deposition onto a stainless-steel target surface. High conversion ratios of D-fructose into 5-hydroxymethylfuraldehyde (5-HMF), 5-methoxymethylfuraldehyde (5-MMF), and difructrose anhydrides (DFAs) were obtained with HCl and KHSO4 as metal-free catalysts by using synthetic conditions under which the same products in bulk are not formed. Furthermore, the reaction outcome was found to be highly sensitive to the catalyst and the solvent employed as well as to the ESI source parameters influencing the thin film formation from microdroplets deposition onto the solid surface
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