A cascade transformation of C2-quaternary indoxyls leading to an efficient assembly of complex (dihydro)indolo[1,2-]quinolin-5-one ring systems is reported. The method involves the gram-scale preparation of 2-(2-aryl-3-oxoindolin-2-yl)-2-phenylacetonitriles which are then converted with methyl ketones to the corresponding 2-(2-oxo-2-aryl(alkyl)ethyl)-2-phenylindolin-3-ones. The latter can either be isolated with good yields (75-96%) or, in the case of -nitroacetophenone, used for further base-assisted intramolecular SAr cyclization resulting in indoxyl-fused quinolone-4 hybrids (up to 95%).
View Article and Find Full Text PDFMetabolites
October 2024
Objectives: The present study aimed to assess the effects of blackcurrant (BC) anthocyanins on concentrations of microbial-derived short-chain carboxylic acids (SCCAs) and metabolites of phytoestrogens. We then examined their associations with six-month changes in whole-body bone mineral density (BMD) and biomarkers of bone metabolism.
Methods: Fecal and blood samples from a pilot randomized controlled trial were collected and analyzed from 37 eligible peri- and early postmenopausal women aged 45-60 years who were randomized into one of three treatment groups consuming one placebo capsule (control), 392 mg BC (low BC) or 784 mg BC (high BC) daily for six months.
J Org Chem
October 2024
Herein, we describe a novel reaction between C-2-substituted indoles and 2-nitroacetophenones leading to a variety of indole-containing heterocyclic scaffolds. At 60 °C in AcOH with HSO as catalyst, C-2 aryl indoles give 3-(2-nitrovinyl)-indoles with high or geometric selectivity depending on the type of substrate utilized. These compounds undergo an electrocyclization process in a sealed vial in a microwave apparatus in DMF at 250 °C to give benzo[]carbazoles and naphtho[2,1-]carbazoles depending on whether the C-2 aromatic moiety is phenyl or naphthyl.
View Article and Find Full Text PDFWetlands occupy up to 35% of the boreal biome in Russia, according to various estimates. Boreal bogs are global carbon sinks, accounting for more than 65% of the soil carbon stored in the wetland ecosystems of the world. The decomposition of plant residues is one of the most important components of the carbon cycle in wetland systems, while the violation of their fragile balance due to climate change increases the rate of mineralisation of organic matter and releases large amounts of carbon to the atmosphere.
View Article and Find Full Text PDFA new variant of Fisher indole synthesis involving Bronsted acid-catalyzed hydrohydrazination of unactivated terminal and internal acetylenes with arylhydrazines is reported. The use of polyphosphoric acid alone either as the reaction medium or in the presence of a co-solvent appears to provide the required balance for activating the C-C triple bond towards the nucleophilic attack of the hydrazine moiety without unrepairable reactivity loss of the latter due to competing amino group protonation. Additionally, the formal hydration of acetylenes to the corresponding ketones occurs under the same conditions, making it an alternative approach for generating carbonyl groups from alkynes.
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