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[Display omitted] • HReO 4 as a novel and efficient catalyst for the conversion of carbohydrates into EL, EMF, HMF and LA. • HReO 4 catalyzes four selective reactions with excellent yields. • HReO 4 promotes the synthesis of EL, HMF, LA and EMF from inulin and sucrose in moderate to good yields. • HReO 4 can be use in at least 12 catalytic cycles on the conversion of fructose into LE with good activity. • HReO 4 can be applied for the production of LE, EMF, HMF and LA in gram scale with good yields. This work describes the first catalyst (HReO 4) that promotes the efficient and selective conversion of several carbohydrates into four compounds, ethyl levulinate (EL), 5-ethoxymethylfurfural (EMF), 5-hydroxymethylfurfural (HMF) and levulinic acid (LA), through a one-pot reaction strategy adjusting the reaction conditions. The reaction of fructose in ethanol at 160 °C gave EL in 80% yield after 16 h and in a mixture of ethanol/THF at 140 °C produced EMF in 73% yield after 1 h. HMF and LA can also be obtained selectively with 100% yield from fructose at 140 °C after 1 h, in DMSO or 1,4-dioxane, respectively. EL, HMF, LA and EMF were also produced in moderate to good yields from other carbohydrates such as inulin and sucrose. The catalyst HReO 4 can be used in gram scale for the production of EL, EMF, HMF and LA with good yields and in at least 8 catalytic cycles on the conversion of fructose into EL with no significant reduction in its activity. [ABSTRACT FROM AUTHOR]

The synthesis of novel types of furanosyl nucleoside analogues, namely N‐(benzyltriazolyl)methyl glucuronamide derivatives, N‐dodecyl glucuronamide‐based phenyltriazole nucleosides, and theobromine xylosyl 5′‐isonucleosides, as potential cholinesterase inhibitors is described herein. O‐Substituted and partially O‐substituted N‐propargyl glucuronamides, accessed from glucofuranurono‐6,3‐lactone, were engaged in CuI‐catalyzed cycloaddition with benzyl azide, whereas their N‐dodecyl uronamide counterparts were converted in three steps into glycosyl azides, which were subjected to cycloaddition with phenylacetylene. A xylofuranose derivative having a free 5‐OH group was coupled with theobromine by Mitsunobu reaction and the obtained isonucleoside was functionalized at C‐1′ with a sulfonamide moiety, leading to a prospective nucleotide mimetic. Five compounds displayed selective inhibition of acetylcholinesterase in the micromolar concentration range, with an α‐glycosyl triazole (Ki = 3.53 µm) and its 1‐azido‐uronamide precursor (Ki = 1.73 µm) being the most active. Docking studies were performed to give insights into the different inhibitory behavior within glycosyl azide anomers. Two of the best inhibitors showed low toxicity in both a neural cell line and human fibroblasts, rendering them promising lead compounds and supporting further investigations. [ABSTRACT FROM AUTHOR]

The synthesis of purine/triazole 6'-isonucleosides and of glucuronic acid/glucuronamide-derived N-glycosylsulfonohydrazides through efficient and stereo- or regioselective methodologies is described. Their structures were envisaged to mimic nucleosides, sugar phosphates, or nucleotides, and were expected to provide potential inhibitors of therapeutically relevant enzymes, the active sites of which could potentially bind their structural fragments or functional groups. Such enzymes include cholinesterases, carbonic anhydrase II (CA-II) and cyclin-dependent kinase 2 (CDK-2). A (triazolyl)methyl amide-linked disaccharide nucleoside, based on a new prospective structural framework for analogues of nucleoside diphosphate sugars, was synthesized. The synthetic strategies employed unprotected or partially protected carbohydrate derivatives as precursors, including ribose, glucuronic acid, glucuronolactone, and glycopyranosides and relied on stereoselective N-glycosylation, regioselective Mitsunobu coupling and 'click chemistry' approaches. Some 6'-isonucleosides and triazole-containing glycoderivatives displayed moderate selective acetylcholinesterase inhibitory activities. The best inhibitor was an aminomethyltriazole 6'-isonucleoside with a Ki value of 11.9 μM. N-Glucuronylsulfonohydrazide showed good inhibition of CA-II (Ki = 9.5 μM). Molecular docking of the most active compounds into the effected enzymes showed interactions with key amino acid residues for substrate recognition. In addition, the tested compounds did not show toxicity to normal cells. [ABSTRACT FROM AUTHOR]

• One-pot sustainable synthesis of valuable nitrogen compounds from biomass resources. • One-pot synthesis of quinazolines from carbohydrates. • One-pot synthesis of 2-furfurylidene derivatives from carbohydrates. • HReO 4 as an efficient catalyst for the conversion of carbohydrates into nitrogen compounds. In this work we report a new one-pot process for the sustainable synthesis of 2-furanylquinazolines and 2-furfurylidene derivatives from carbohydrates, including xylose, fructose and xylan, with moderate overall yields, catalyzed by perrhenic acid. [Display omitted] [ABSTRACT FROM AUTHOR]