18385-84-7Relevant articles and documents
Synthesis of pterocarpans through palladium-catalyzed oxyarylation of alkoxy-2H-chromenes with o-iodophenols
Gaspar, Francisco V.,Barcellos, Julio C.F.,Cívicos, José F.,Merino, Pedro,Nájera, Carmen,Costa, Paulo R.R.
, (2020/10/22)
The oxyarylation of alkoxy-2H-chromenes (1a-e) with o-iodophenols substituted by electron-withdrawing (CHO) and electron-donating (OMe) groups is studied under two experimental conditions: a) Pd(OAc)2, Ag2CO3 in PEG-400 at 140 °C, 10 min and b) oxime-based palladacycle, DIPEA, in PEG-400 at 150 °C, 3–4 h. Pterocarpans are obtained in moderate to good chemical yields.
Silica-immobilized NHC-gold(I) complexes: Versatile catalysts for the functionalization of alkynes under batch and continuous flow conditions
Sarmiento, Jeymy T.,Suárez-Pantiga, Samuel,Olmos, Andrea,Varea, Teresa,Asensio, Gregorio
, p. 7146 - 7155 (2017/11/06)
Immobilized sterically demanding NHC-Au(I) complexes silica-[(IPrR)Au]Cl and silica-[(IAdPrR)Au]Cl are synthesized and characterized. These complexes are suitable catalysts in typical homogeneous Au(I)-catalyzed alkyne reactions such
A novel solid-phase synthesis of 2H-chromenes
Tang,Zhao, Yinjiao,Zhang, Meng,Dai, Xin,Wang, Weilin,Mao, Deshou
, p. 708 - 719 (2016/05/09)
A method for synthesizing substituted 2H-chromenes using TMSOTf-catalyzed polystyrene-supported succinimidyl selenide-induced intramolecular seleno-arylation of tethered alkenes as a key step has been developed. The catalytic process provides an efficient
2H-chromenes generated by an iron(III) complex-catalyzed allylic cyclization
Calmus,Corbu,Cossy
, p. 1381 - 1386 (2015/05/19)
A straightforward method based on an iron(III) complex-catalyzed cyclization of 2-(1-hydroxyallyl)phenols is reported to access a large variety of 2H-chromenes. This method was applied to the total synthesis of a natural product, tephrowatsin B.
Indium-catalyzed intramolecular hydroarylation of aryl propargyl ethers
Alonso-Maran, Lorena,Martnez, M. Montserrat,Sarandeses, Luis A.,Sestelo, Jos Prez
, p. 379 - 387 (2015/02/02)
Indium(iii) halides catalyze efficiently the intramolecular hydroarylation (IMHA) of aryl propargyl ethers. The reaction proceeds regioselectively with terminal and internal alkynes bearing electron-rich and electron-deficient substituents in the benzenes
Gold nanoparticles supported on TiO2 catalyse the cycloisomerisation/oxidative dimerisation of aryl propargyl ethers
Efe, Christina,Lykakis, Ioannis N.,Stratakis, Manolis
, 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.
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
, 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
A highly adaptable catalyst/substrate system for the synthesis of substituted chromenes
Aponick, Aaron,Biannic, Berenger,Jong, Michael R.
supporting information; experimental part, p. 6849 - 6851 (2010/10/21)
The gold(i)-catalyzed endo-cyclization of o-(1-hydroxyallyl)phenols to form chromenes is reported. The title compounds are prepared in high yield from readily available substrates. The system tolerates both electron rich and deficient aryl rings and a high degree of substitution on the allyl moiety.
The Au(I)-catalyzed intramolecular hydroarylation of terminal alkynes under mild conditions: Application to the synthesis of 2H-chromenes, coumarins, benzofurans, and dihydroquinolines
Menon, Rajeev S.,Findlay, Alison D.,Bissember, Alex C.,Banwell, Martin G.
supporting information; experimental part, p. 8901 - 8903 (2010/03/01)
(Chemical Equation Presented) Operationally simple Au(I)-catalyzed intramolecular hydroarylation (IMHA) reactions of terminal alkynes that proceed in high yield and under very mild conditions are described. These processes involve low catalyst loadings, mild reaction temperatures, and short reaction times, require no cocatalysts or additives, and allow for the generation of a number of important heterocyclic motifs from readily accessible starting materials.
Synthesis of 2H-chromenes through the reduction of chromones with 9-BBN
Eguchi,Hoshino
, p. 967 - 970 (2007/10/03)
Chromones were regioselectively reduced to 2H-1-benzopyrans through the 1,2-addition of 9-borabicyclo-[3.3.1]nonane. Although transition-metal complexes did not have a catalytic effect on the reaction, only by using palladium(II) chloride, could both 2H-1-benzopyran and dihydro-1-benzopyran be obtained to a similar extent. Also, the reduction of chromone using other organoboranes led not to 2H-1-benzopyran, but rather to chromanone through the reduction of only an olefin moiety.
