Showing papers on "Benzopyrans published in 2007"
TL;DR: The electrophilic cyclization of substituted propargylic aryl ethers by I2, ICl, and PhSeBr produces 3,4-disubstituted 2H-benzopyrans in excellent yields.
Abstract: The electrophilic cyclization of substituted propargylic aryl ethers by I2, ICl, and PhSeBr produces 3,4-disubstituted 2H-benzopyrans in excellent yields. This methodology results in vinylic halides or selenides under mild reaction conditions and tolerates a variety of functional groups, including methoxy, alcohol, aldehyde, and nitro groups.
140 citations
TL;DR: Modification of the C-ring disrupts binding to ERalpha, thus improving ERbeta selectivity up to 100-fold, and syntheses of cyclopentanone and cyclohexanone intermediates for SAR studies of theC-ring on the benzopyran scaffold are described.
46 citations
TL;DR: In this paper, a substitution at the 8-position of the benzopyran A-ring was proposed to disrupt binding to ERα, thus improving ERβ subtype selectivity.
41 citations
TL;DR: Modification of both positions proved additive, maintaining affinity and improving ERbeta selectivity up to 83-fold, and confirming the previously observed binding mode in ERbeta.
38 citations
TL;DR: X-ray crystal structures of 5b and a non-selective analog 5c in ERalpha help explain the observed selectivity of the benzopyran platform.
35 citations
TL;DR: The benzopyrans provide a template for the synthesis of potent and selective K(V)1.5 blockers, which have the potential to be atrium-selective agents for treatment of atrial fibrillation.
33 citations
TL;DR: In this paper, a stable pallada cycle with sp3-hybridized stereogenic carbon and bipyridine or bisimine auxiliary ligands (L-L) was shown to operate as an intermediate in the reaction sequence, which was detected by lowtemperature 1H NMR analysis and characterized by X-ray crystallography.
32 citations
TL;DR: The unique photochromic bis-chromene 5 incorporates the structural attributes of both 3 and 4 and leads to a dark brown colour, which is formed by mixing the purple and red colours observed for the photolysates of3 and 4 , respectively.
Abstract: The unique photochromic bis-chromene 5 incorporates the structural attributes of both 3 and 4. UV–vis irradiation of 5 leads to a dark brown colour, which is formed by mixing the purple and red colours observed for the photolysates of 3 and 4, respectively.
18 citations
TL;DR: In this article, a simple catalytic racemic synthesis of benzopyranes, benzothiopyranes and 1,2-dihydroquinolines is presented.
Abstract: A simple catalytic racemic synthesis of benzopyranes, benzothiopyranes and 1,2-dihydroquinolines is presented. The organocatalytic domino reactions between 2-heteroatom substituted aldehyde derivatives and ?,?-unsaturated aldehydes or ?,?-unsaturated cyclic ketones proceed with excellent chemoselectivity to give the corresponding products in good to high yields.
15 citations
TL;DR: In this article, a quantitative structure-activity relationship (QSAR) study was performed using E-state and R-state indices along with Wang-Ford charges, n-octanol/water partition coefficient, molar refractivity, and indicator parameters.
Abstract: R/S-3,4-Dihydro-2,2-dimethyl-6-halo-4-(substituted phenylaminocarbonyl-amino)-2H-1-benzopyrans are pancreatic β-cells potassium (KATP-pβ) channel openers with inhibitory effect on insulin secretion. To find the more active and effective benzopyrans as selective potassium (KATP-pβ) channel openers towards the pancreatic tissues, quantitative structure–activity relationships (QSAR) study was performed using E-state and R-state indices along with Wang–Ford charges, n-octanol/water partition coefficient, molar refractivity, and indicator parameters. QSAR models were developed by statistical techniques, e.g., multiple linear regression (MLR), principle component regression analysis (PCRA), and partial least squares (PLS) analysis. The generated equations were validated by the leave-one-out cross-validation method. The models show the importance of ETSA indices of atom numbers 16, 17, 18, 19, 21 as well as 22. The positive coefficient of S16, S17, S18, S19, S21, and S22 indicate that with the increase of the va...
6 citations
TL;DR: The electrophilic cyclization of substituted propargylic aryl ethers by I2, ICl, and PhSeBr produces 3,4-disubstituted 2H-benzopyrans in excellent yields.
Abstract: The electrophilic cyclization of substituted propargylic aryl ethers by I2, ICl, and PhSeBr produces 3,4-disubstituted 2H-benzopyrans in excellent yields. This methodology results in vinylic halides or selenides under mild reaction conditions and tolerates a variety of functional groups, including methoxy, alcohol, aldehyde, and nitro groups.
TL;DR: The reaction of homophthaldehyde with 8-(benzylamino)menthol is regio-and diastereo-selective, leading to the chiral perhydro-1,3-benzoxazine 3 as a single diastereoisomer as discussed by the authors.
Abstract: The reaction of homophthaldehyde with (–)-8-(benzylamino)menthol is regio- and diastereo-selective, leading to the chiral perhydro-1,3-benzoxazine 3 as a single diastereoisomer. The addition of different organometallics to 3 yielded alcohols 4 in excellent yields. Hydrolysis of carbinols, with 2 % HCl in methanol or ethanol, allowed for the synthesis of 1,3-disubstituted isochromanes, but hydrolysis in toluene led to enantiopure 1-substituted isochromenes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)