Showing papers in "Tetrahedron Letters in 2021"

TL;DR: In this article, a comprehensive exposure to assess indole heterocycles by conventional methods and also ingraining special advanced techniques is presented, to the best of our acquaintance, a comprehensive evaluation of these compounds is provided.

TL;DR: In this article, a low-cost catalyst for the synthesis of symmetrical / unsymmetrical thiosulfonates via the disproportionate coupling reaction of sulfonyl hydrazide was proposed.

TL;DR: In this paper, a review provides a focus on the synthetic approaches towards 1,2,4-triazole derivatives from common precursors such as amidines, imidates, amidrazones, aryldiazoniums and hydrazones.

TL;DR: In this article, a facile and efficient synthesis of homoallylic amines by visible-light photoredox-promoted desilylative allylation of α-silylamines with allylic sulfones is described.

TL;DR: Visible light promoted eosin Y catalyzed selective C3-H acylation of quinoxalin-2(1H)-ones has been developed in a green and sustainable manner as mentioned in this paper.

TL;DR: In this article, the authors reviewed 12 representative synthetic examples published recently, to showcase the power of these reactions in the construction of contiguous all-carbon quaternary centers and inspire future exploration.

TL;DR: In this article, a benzothiazole-based azo compound was synthesized and evaluated as a probe for the selective sensing of cations and anions in aqueous media.

TL;DR: An efficient visible-light-induced C H arylation of quinoxalin-2(1H)-ones in H2O is developed in this paper, which has the advantages of mild reaction conditions, environmental friendliness and good functional group tolerance.

TL;DR: In this article, a metal-free visible light photoredox-catalyzed synthesis of enaminosulfones from vinyl azides and sodium sulfinates in moderate to high yields is described.

TL;DR: In this paper, a salen ligand was prepared in high yield and their cytotoxic activities were evaluated against the Human Colon cancer HCT116 cell lines, demonstrating the benefit of the bridging backbone compared to other salen systems.

TL;DR: The Dπ-A-π-D type tetraphenylethene-based cyanostilbene derivative TPEAN had been designed and synthesized as mentioned in this paper, which gradually formed and emitted intense fluorescence at high water content in a mixture of THF/water.

TL;DR: A convenient protocol for amide bond formation for electron deficient amines and carboxylic acids is described in this article, which is amenable to the synthesis of a range of functionalized amide derivatives with electron deficient and unreactive amines.

TL;DR: A Bronsted acid-promoted trifluoromethylselenolation of benzofurans was reported in this paper, using SeCF3-substituted benzofuran derivatives in moderate to good yields with excellent regioselectivity.

TL;DR: In this paper, two novel Hg2+ fluorescent probes W-5 and W-6 have successfully been designed and synthesized based on benzothiazole derivatives as fluorophores and thiocarbonate moiety as recognition group.

TL;DR: In this paper, the authors discuss various related issues such as free-energy-based Boltzmann distribution of flexible molecules, multistandard or multinuclear conversion of σXs to δXs, linear regression of calculated NMR parameters, etc.

TL;DR: In this article, an efficient DTBP-promoted direct alkylation of quinoxaline-2(1H)-ones with aldehydes has been developed under metal-free conditions.

TL;DR: An environmentally friendly method of electrochemical mediated regioselective C-3 trifluoromethylation of 2H-indazole by employing CF3SO2Na as the CF3 source was described in this article.

TL;DR: In this article, a dual catalytic system involving a merger of photoredox catalysis and 4-acetamido-TEMPO is employed to carry out this oxidation process.

TL;DR: In this article, a microwave assisted ligand-free palladium-catalyzed post Ugi reaction was used for the synthesis of isoquinolone and pyrazole mixed pharmacophore derivatives.

TL;DR: Visible light-induced radical aryldifluoromethylation of N-arylacrylamides using [bis(difluoroacetoxy)iodo]benzene as a diffluoromethodine reagent is reported for the first time in this article.

TL;DR: In this paper, the α-aminoalkyl radical is regioselective compared with the previous reports, and the reaction was successfully performed without additional additives under mild conditions.

TL;DR: An efficient route for the difluorinative-hydroxylation through dearomative difunctionalization of imidazopyridine using Selectfluor as fluorine source has been developed in an aqueous medium and provided wide functional group tolerance, metal/ base-free, and green approach.

TL;DR: In this article, a facile and efficient synthesis of naphthoquinone-based chalcone hybrids (7 and 24) via the microwave-assisted one-pot three-component reactions of 2-substituted-1,4-naphthoequinones, N,N-dimethylformamide dimethyl acetal (DMF-DMA), and acetophenone derivatives has been reported.

TL;DR: In this paper, two new organoboron salicylaldehyde-based acylhydrazone derivatives DPDP (2-(10-(diethylamino)-2-phenylbenzo[h][1-3,5,6]dioxadiazaboronin-4-yl)phenol) and DPDN (1-(10-diethenyl-2)-phenyl-benzo [h] naphthalen-2-ol) were successfully synthesized and characterized.

TL;DR: In this paper, a review of the recent progress of the nickel-catalyzed dehydrogenative coupling of alcohols to synthesize the N-heterocycles, their substrate scope and a brief discussion of the mechanism are presented.

TL;DR: The simple mixture of nuclear fast red (NFR) and Hg2+ containing poly(diallyldimethylammonium chloride) (PDADMAC) was found to be colorimetric detection for iodide ion in aqueous solution via the indicator displacement assay.

TL;DR: In this article, a direct and efficient protocol for thiocyanation of imidazoheterocycles accompanying with the hydrogen evolution under electrochemical oxidation has been described, which can easily be scaled up.

TL;DR: In this article, a rapid metal and additive-free method for C(sp2)-H thiocyanation of pyrazoles under visible light at room temperature was described.

TL;DR: In this paper, the advances of sodium sulfinates in radical reactions (2010-2021) were summarized via three mechanisms: (1) sulfonyl radicals (2) RS radicals; (3) trifluoromethyl radicals.

TL;DR: In this paper, a practical and efficient H/D exchange method for selective deuteration of terminal alkynes was disclosed, which was performed with CF3COOAg as catalyst at room temperature, affording products with high level of deuterium incorporation.