22927-97-5Relevant academic research and scientific papers
Gold(I)-Catalyzed Intramolecular Hydroarylation of Phenol-Derived Propiolates and Certain Related Ethers as a Route to Selectively Functionalized Coumarins and 2 H-Chromenes
Cervi, Aymeric,Vo, Yen,Chai, Christina L. L.,Banwell, Martin G.,Lan, Ping,Willis, Anthony C.
, p. 178 - 198 (2020/12/22)
Methods are reported for the efficient assembly of a series of phenol-derived propiolates, including the parent system 56, and their Au(I)-catalyzed cyclization (intramolecular hydroarylation) to give the corresponding coumarins (e.g., 1). Simple syntheses of natural products such as ayapin (144) and scoparone (145) have been realized by such means, and the first of these subject to single-crystal X-ray analysis. A related process is described for the conversion of propargyl ethers such as 156 into the isomeric 2H-chromene precocene I (159), a naturally occurring inhibitor of juvenile hormone biosynthesis.
Enhanced enantioselectivity in heterogeneous manganese-catalyzed asymmetric epoxidation with nanosheets modified amino acid Schiff bases as ligands by modulating the orientation and the arrangement order
An, Zhe,Han, Hongbo,He, Jing,Jiang, Yitao,Ping, Qi,Shu, Xin,Song, Hongyan,Tang, Yuanzhong,Wang, Wenlong,Xiang, Xu,Zhu, Yanru
, p. 22 - 36 (2021/08/25)
Catalytic enantioselective epoxidation of olefins plays an important role in the production of optically-active epoxy. Transition-metal complexes prove efficient for the catalytic epoxidation of un-functionalized olefins by employing privileged chiral lig
Boronic acid/Br?nsted acid co-catalyst systems for the synthesis of 2: H -chromenes from phenols and α,β-unsaturated carbonyls
Dimakos, Victoria,Singh, Tishaan,Taylor, Mark S.
, p. 6703 - 6711 (2016/07/21)
Protocols for the synthesis of substituted 2H-chromenes from α,β-unsaturated carbonyls and phenols are described. Optimal combinations of arylboronic acids and Br?nsted acids have been identified, such that both can be employed in catalytic quantities to accelerate these condensations. The method has been used to synthesize a variety of substituted 2H-chromenes, as well as photochromic naphthopyrans. The use of pentafluorophenylboronic acid and diphenylphosphinic acid enabled an expansion of the electrophile scope to include α,β-unsaturated ketones. Hall's 'phase-switching' of boronic acids has been exploited to achieve the separation of the two co-catalysts from unpurified reaction mixtures by a simple liquid-liquid extraction.
USE OF COMPOSITIONS OBTAINED BY CALCINING PARTICULAR METAL-ACCUMULATING PLANTS FOR IMPLEMENTING CATALYTICAL REACTIONS
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Paragraph 0828, (2016/01/25)
The use of metal-accumulating plants for implementing chemical reactions especially catalytical reactions.
An efficient and simple method for synthesis of 2,2-disubstituted-2H- chromenes by condensation of a phenol with a 1,1-disubstituted propargyl alcohol using BF3·Et2O as the catalyst
Madabhushi, Sridhar,Jillella, Raveendra,Godala, Kondal Reddy,Mallu, Kishore Kumar Reddy,Beeram, China Ramanaiah,Chinthala, Narsaiah
supporting information, p. 5275 - 5279 (2012/11/13)
An efficient and simple method for the synthesis of 2,2-disubstituted-2H- chromenes by one-step cyclocondensation of a phenol with a variety of 1,1-disubstituted propargyl alcohols using BF3·Et2O as the catalyst is described.
Ph3PAuNTf2 as a superior catalyst for the selective synthesis of 2H-chromenes: Application to the concise synthesis of benzopyran natural products
Lykakis, Ioannis N.,Efe, Christina,Gryparis, Charis,Stratakis, Manolis
experimental part, p. 2334 - 2338 (2011/06/20)
Ph3PAuNTf2 (≈1 mol-%) catalyzes the selective cycloisomerization of substituted aryl propargyl ethers into 2H-chromenes in excellent yields. Benzofuran byproducts are formed only in the case of electron-deficient arenes, in up to 7% relative yield. The Ph 3PAuNTf2-catalyzed cyclization of aryl propargyl ethers was applied as a key step to the concise synthesis of the naturally occurring benzopyrans seselin, xanthyletin, precocenes I and II, 8-(3′,3′- dimethylallyl)wenteria chromene, and 2,2-dimethyl-8-prenylchromene-6-propenoic acid. Ph3PAuNTf2 is a general, highly efficient, and product-selective catalyst for the clean synthesis of 2H-chromenes from the cycloisomerization of aryl propargyl ethers.The Ph3PAuNTf 2-catalyzed cyclization was applied as a key step in the synthesis of several benzopyran-bearing naturally occurring substances. Copyright
ReCl(CO)5-catalyzed cyclocondensation of phenols with 2-methyl-3-butyn-2-ol to afford 2,2-dimethyl-2H-chromenes
Zeng, Hanxiang,Ju, Jia,Hua, Ruimao
supporting information; experimental part, p. 3926 - 3928 (2011/08/06)
A direct one-pot route for the synthesis of 2,2-dimethyl-2H-chromenes by Re(CO)5Cl-catalyzed cyclocondensation of phenols with 2-methyl-3-butyn-2-ol has been developed. The easy availability of starting materials, mild reaction conditions, high
Gold nanoparticles supported on TiO2 catalyse the cycloisomerisation/oxidative dimerisation of aryl propargyl ethers
Efe, Christina,Lykakis, Ioannis N.,Stratakis, Manolis
supporting information; body text, p. 803 - 805 (2011/04/12)
Gold nanoparticles supported on TiO2 (～1%) catalyse in high yields the selective cycloisomerisation of aryl propargyl ethers into the corresponding 2H-chromenes, under heterogeneous conditions. 2H,2′H-3, 3′-Bichromenes resulting from a catalytic oxidative dimerization pathway are also formed as by-products. The Royal Society of Chemistry 2011.
A simple two steps ytterbium triflate-catalysed preparation of 2,2-dimethyl-2H-chromenes from salicylaldehydes and 2-methylpropene
Prado, Soizic,Janin, Yves L.,Bost, Pierre-Etienne
, p. 1605 - 1608 (2007/10/03)
The preparation of various 2,2-dimethyl-2H-chromenes was achieved in two steps via an ytterbium triflate-catalysed reaction between salicylaldehydes, trimethylorthoformate and 2-methylpropene. From salicylaldehyde, two reaction products were characterised
BENZOPYRAN COMPOUND
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Page/Page column 89, (2010/02/13)
This invention relates to benzopyran compounds of formula (I) wherein X is NR6, Y is a bond, SO or SO2, Z is C1-4alkyl group or phenyl group, W is hydrogen atom, hydroxy group, C1-6 alkoxy group, a halogen atom,
