Showing papers on "Benzopyrans published in 2013"
TL;DR: An enantioselective cascade Michael-Michael reaction between chalcones enolates and nitromethane catalyzed by a bifunctional thiourea is developed, which provides a mild but efficient approach to chiral benzopyrans bearing three consecutive stereocenters.
Abstract: An enantioselective cascade Michael–Michael reaction between chalcones enolates and nitromethane catalyzed by a bifunctional thiourea is developed. This reaction provides a mild but efficient approach to chiral benzopyrans bearing three consecutive stereocenters in high yields with excellent stereoselectivities, and the benzopyrans can be easily transformed to the corresponding tricyclic product.
52 citations
TL;DR: 2-Aryl-3-hydroxy-2-cyclohexenones are shown to be competent substrates for palladium- and ruthenium-catalyzed C-H alkenylation reactions with terminal alkenes, providing, in most cases, benzopyrans.
49 citations
TL;DR: The authors showed that benzopyrans sharing one hydroxyl/methoxyl and containing an additional benzylidenyl or a spirocyclohexyl motif are able to induce ERE-dependent transcription in breast carcinoma cells.
Abstract: Molecules with potent estrogenic activity are ~270 A3 hydrophobic structures that encompass two hydroxyls among which is at least one phenol. However, compounds with only one phenol or devoid of such a ring have been shown to enhance ERα-mediated transcription at concentrations much larger than those measured with E2. In this context, we show here that benzopyrans sharing one hydroxyl/methoxyl and containing an additional benzylidenyl or a spirocyclohexyl motif are able to induce ERE-dependent transcription in breast carcinoma cells.
13 citations
TL;DR: A review of reaction chemistry and new ring synthetic methods for pyrans can be found in this article, which covers work published in the calendar year 2012 and includes new ring synthesis methods for Pyranones, dihydro-benzopyrans, isochromenes, ischromans, coumarins, chromones, xanthenes, xanthones, thiopyrans and oxathians.
Abstract: This review covers work published in the calendar year 2012. Novel reaction chemistry and new ring synthetic methods for pyrans, [1]benzopyrans, dihydro[1]benzopyrans (chromenes, chromans), [2]benzopyrans, dihydro[2]benzopyrans (isochromenes, isochromans), pyranones, coumarins, chromones, xanthenes, xanthones, thiopyrans, dioxins, dioxanes, trioxanes, tetraoxanes, dithianes, trithianes, and oxathianes are reviewed.
5 citations
TL;DR: The use of microwave assisted organic reactions has attracted considerable attention in organic synthesis because of their simplicity, greater selectivity, and rapidity in operation, for the synthesis of a variety of organic compounds.
Abstract: In recent years, the synthesis of benzopyran derivatives has attracted great interest. Since the discovery of cromakalim as a typical ATP-sensitive potassium channel opener (PCO), a large number of benzopyran derivatives have been synthesized and demonstrated to possess potent relaxant activity on blood vessels, cardiac muscle and other smooth muscles 1 . These agents may find use in the treatment of a variety of diseases such as hypertension, asthma, ischemia and urinary incontinence. The pyran pharmacophore is an important core structure of many natural products showing antibacterial, antitumor, antiallergic, antibiotic, hypolipidemic and immunoodulating activities 2,3 . When the hydrogen atom of pyran ring is substituted by amino or cyano, they become synthons 4,5 of some natural products. Microwave assisted organic reactions have attracted considerable attention in organic synthesis because of their simplicity, greater selectivity, and rapidity in operation, for the synthesis of a variety of organic compounds 6-8 . Recently, more interest has been focused on “dry media” synthesis using inorganic solid supports. The coupling of microwave heating mode with the use of mineral solid support 9-11
2 citations
TL;DR: In this article, 2-Aryl-3-hydroxy-2-cyclohexenones are shown to be competent substrates for palladium and ruthenium-catalyzed C-H alkenylation reactions with terminal alkenes, providing, in most cases, benzopyrans.
Abstract: 2-Aryl-3-hydroxy-2-cyclohexenones are shown to be competent substrates for palladium- and ruthenium-catalyzed C–H alkenylation reactions with terminal alkenes, providing, in most cases, benzopyrans.
1 citations
01 Feb 2013
TL;DR: Amino-4-aryl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-1benzopyran-3-carbonitriles as mentioned in this paper has been synthesized conveniently by treating dimedone (5,5-dimmethyl-1,3-cyclohexanedione) 1 with arylidenemalononononitriitrivanonitrivanitrivanone 2 in the presence of lithium chloride in dry media using basic alumina as
Abstract: 2-Amino-4-aryl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-1benzopyran-3-carbonitriles 3 have been synthesized conveniently by treating dimedone (5,5-dimethyl-1,3-cyclohexanedione) 1 with arylidenemalononitriles 2 in the presence of lithium chloride in dry media using basic alumina as solid support under microwave irradiation with very good yields.
1 citations
TL;DR: The title reaction as discussed by the authors provides a mild and efficient approach for the synthesis of the chiral benzopyrans (III and VI) with three consecutive stereocenters, and can be used to synthesize chiral polytopes as well.
Abstract: The title reaction provides a mild and efficient approach for the synthesis of the chiral benzopyrans (III) and (VI) with three consecutive stereocenters.
1 citations