Hribernik, NivesChiodo, FabrizioPieters, Roland J.Bernardi, Anna...
5页
查看更多>>摘要：Recruitment of natural antibodies towards tumour cells for their elimination by the immune system could be a highly specific and efficacious therapeutic strategy. While natural L-rhamnose has already been explored as a suitable antigen for antibody recruitment, we here report the first rhamnose-based glycomimetic to be used for such purpose. The glycomimetic is designed to be more hydrolytically and enzymatically stable than natural rhamnosides, provides a site for easy further conjugation and proved to capture anti-rhamnose IgG antibodies in serological ELISA assay.(c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
查看更多>>摘要：We present a visible light-activated ruthenium-catalysed direct arylation of aryl C-H bonds with aryl (pseudo)halides, which operates at ambient temperature with broad substrate scopes and excellent compatibility of functionalities. The key to success of this strategy is the efficient generation of active catalytic species via photo-induced ligand dissociation. The choices of the bases and solvents also have significant influence on the catalytic efficiency. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：This article reports the regioselective and chemoselective synthesis of 4,5-dialkoxy-2-nitroanilines substituted with two alkoxys at C-4 and C-5. Here we show the optimization protocol of the transetherification reaction used to synthesize 20 new compounds with good to excellent yields (50-92%). We describe a simple and efficient one-step procedure that can be applied to obtain a significant number of pharmacologically active compounds, including antimalarial drug Primaquine analogs. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Han, MeiShen, Mei -HuaZhu, Chi -FanXu, Hua -Dong...
4页
查看更多>>摘要：A series of gamma-lactams were synthesized by intramolecular aza-claisen rearrangement of ketenes using Meldrum's acid as ketene precursor. Derivatives of Meldrum's acid with tertiary ammonia structure were used as raw material, and the reaction was catalyzed by Lewis acid at high-temperature conditions under microwave. Ketene formation by losing acetone and CO2, cyclization and claisen rearrangement occurred in sequence to form the gamma-lactams. (C) 2022 Elsevier Ltd. All rights reserved.
Fernandez-Canelas, PaulaBarrio, PabloGonzalez, Jose M.
17页
查看更多>>摘要：Haloalkynes can enter a wide variety of metal-catalyzed transformation giving rise to the formation of products with or without showing halide-shift. This article offers an overall view of the reactivity of these substrates under gold catalysis. Particular attention is devoted to intramolecular reactions that involve a concomitant halide-shift process for the case of alkynyl iodides as starting materials.(c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
查看更多>>摘要：An efficient and robust Rh(III)-catalyzed three-component C-H esterification reaction of indole derivatives with vinylene carbonate to access indolyl acetates has been developed.This protocol exhibits high efficiency, good yields, and excellent functional group tolerance. Significantly, this method provides a powerful approach for the late-stage modification of indole-based substrates and natural alcohols.(c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A new, green, convenient, cost- and atom effective route leading to 3-arylmethyl 4-hydroxyquinolin-2 (1H)-ones from arylaldehydes and 1,3-dicarbonyl compounds in triethyl ammonium formate in good to excellent yield is presented. The provided method foresees the Knoevenagel condensation between a 4-hydroxyquinolin-2(1H)-one and an aromatic aldehyde followed by in situ trapping of the arylidene intermediate with the hydride ion. All synthesized compounds were tested for their antiradical activity against DPPH and GO free radicals. The antiradical activity of the 3-arylmethyl 4-hydroxyquinolin-2 (1H)-ones was comparable to or even higher than that of some commercially widely used antioxidants like BHT, TBHQ, or a-tocopherol. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：An efficient metal-free approach to access in situ generated tosyldiazomethane (TsDAM) and (Z)-aurones containing pyrazoles under mild conditions has been developed. This methodology involves 1,3-dipolar cycloaddition in an aqueous system, followed by an aromatization with a CAO bond cleavage in an acidic separation environment. We observed good yields under mild conditions, along with synthetic versatility and high functional group compatibility. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：An efficient catalyst-free direct nitration of the C-H bonds of tertiary beta-keto esters using tert-butyl nitrite as a nitrating reagent is described. This radical nitration protocol tolerants diverse functional groups, leading to the preparation of linear and cyclic alpha-nitro-beta-keto ester derivatives in good to excellent yields under mild conditions. In addition, the nitration product 3a was applied to the concise synthesis of a quaternary alpha-amino acid 4 in the presence of zinc power and acetic acid. (C) 2022 Elsevier Ltd. All rights reserved.
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