267901-33-7Relevant articles and documents
Ag2Cr2O7 nanoparticles: An eco-friendly and reusable catalyst for synthesis of pyrano[c]chromenediones and [1,3]dioxolo[g]chromeneones in aqueous media at ambient temperature
Ebrahimi, Mitra,Abdolmohammadi, Shahrzad,Kia-Kojoori, Reza
, p. 1895 - 1902 (2020/05/25)
An efficient and green protocol for the synthesis of 4-aryl-3,4-dihydro-2H,5H-pyrano[3,2-c]chromene-2,5-diones and 8-aryl-7,8-dihydro-6H-[1,3]dioxolo[4,5-g]chromene-6-ones through the Ag2Cr2O7 nanoparticles catalyzed cyclo
N-Heterocyclic Carbene/Potassium Ion Cooperatively Catalyzed Phenylation Reactions of α,β-Unsaturated Acylazoliums
Zheng, Jinhua,Zhu, Kejie,Yuan, Yaofeng,Cheng, Jiajia
, p. 4569 - 4576 (2016/09/24)
A catalytic phenylation reaction of α,β-unsaturated acylazoliums with in-situ-generated phenolates was developed. A combination of N-heterocyclic carbene and potassium ion cooperatively catalyzed the generation of α,β-unsaturated acylazoliums and phenolates from α,β-unsaturated phenolic esters for the efficient [3+3] annulation, which involves a dearomatization–rearomatization process. The approach gives good yields and excellent regioselectivities, and the products could be easily converted into high-value polycyclic derivatives. Mechanistic studies demonstrated that the potassium ion plays a vital role in this reaction.
Molecular iodine catalyst promoted synthesis of chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling
Naik, Mayuri M.,Kamat, Durga P.,Tilve, Santosh G.,Kamat, Vijayendra P.
, p. 5221 - 5233 (2014/07/08)
Molecular iodine as an inexpensive catalyst is described in the construction of 2-substituted or 2,2-disubstituted chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling. For the synthesis of chromans, phenols and allylic alcohols were refluxed in chloroform in presence of 20 mol % I2 while [3+3] cyclocoupling of phenols and cinnamic acids proceeded to give 4-aryl-3,4-dihydrobenzopyran-2-ones using 30 mol % I2. Later reaction occurs via a tandem hydroarylation- esterification process at 120-130°C under solvent free conditions. Chromans were obtained in 20-92% yields and substituted 4-aryl-3,4-dihydrobenzopyran-2- ones were obtained in 5-85% yields.
Molecular iodine catalyst promoted synthesis of chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling
Naik, Mayuri M.,Kamat, Durga P.,Tilve, Santosh G.,Kamat, Vijayendra P.
, p. 5221 - 5233 (2014/12/10)
Molecular iodine as an inexpensive catalyst is described in the construction of 2-substituted or 2,2-disubstituted chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling. For the synthesis of chromans, phenols and allylic alcohols were refluxed in chloroform in presence of 20 mol % I2while [3+3] cyclocoupling of phenols and cinnamic acids proceeded to give 4-aryl-3,4-dihydrobenzopyran-2-ones using 30 mol % I2. Later reaction occurs via a tandem hydroarylation-esterification process at 120-130 °C under solvent free conditions. Chromans were obtained in 20-92% yields and substituted 4-aryl-3,4-dihydrobenzopyran-2-ones were obtained in 5-85% yields.
Sulfonic-acid-functionalized silica: An efficient, heterogeneous and reusable catalyst for the synthesis of 8-aryl-7,8-dihydro-[1,3]dioxolo [4,5-g]chromen-6-ones
Li, Weilin,Wu, Liqiang,Yan, Fulin
experimental part, p. 725 - 728 (2012/07/28)
Sulfonic-acid-functionalized silica was used as an efficient and recyclable catalyst for the one-pot synthesis of 8-aryl-7,8-dihydro-[1,3]dioxolo[4,5-g] chromen-6-ones with the help of 3,4-methylenedioxyphenol, aldehydes and Meldrums' acid. Different type
CeCl3·7H2O as mild and efficient catalyst for the one-pot multicomponent synthesis of 8-aryl-7,8-dihydro[1,3]dioxolo[4,5-g] chromen-6-ones
Wu, Li-Qiang,Li, Wei-Lin,Yan, Fu-Lin
experimental part, p. 235 - 241 (2011/10/30)
A series of new 8-aryl-7,8-dihydro[1,3]dioxolo[4,5-g]chromen-6-ones were synthesized via a three-component reaction of 3,4-methylenedioxyphenol, aromatic aldehydes and Meldrum's acid in the presence of CeCl3·7H 2O under solvent-free
α,β-Unsaturated acyl azoliums from N-heterocyclic carbene catalyzed reactions: Observation and mechanistic investigation
Mahatthananchai, Jessada,Zheng, Pinguan,Bode, Jeffrey W.
supporting information; experimental part, p. 1673 - 1677 (2011/04/21)
Caught in the act: Acyl azoliums have long been thought to be key reactive intermediates in N-heterocyclic carbene catalysis, but they have never been observed under catalytic conditions. Now, this has been successfully achieved by the characterization of α,β-unsaturated acyl azoliums (see scheme) using different spectroscopic techniques. Kinetic studies revealed the origin of their unexpected chemoselectivity in acylation and annulation reactions.
A convenient synthesis of dihydrocoumarins from phenols and cinnamic acid derivatives
Aoki, Shinya,Amamoto, Chie,Oyamada, Juzo,Kitamura, Tsugio
, p. 9291 - 9297 (2007/10/03)
A facile procedure for synthesis of dihydrocoumarin derivatives was described. Although the yield of the products in the reaction of phenols with acrylates in trifluoroacetic acid in the presence of Pd(OAc)2 giving coumarins was found to be very low, dihydrocoumarin derivatives were obtained in good to high yields in the absence of Pd(OAc)2 when ethyl cinnamates bearing electron-donating groups were employed in this reaction.
New Method for Preparation of Coumarins and Quinolinones via Pd-Catalyzed Intramolecular Hydroarylation of C-C Triple Bonds
Jia, Chengguo,Piao, Dongguo,Kitamura, Tsugio,Fujiwara, Yuzo
, p. 7516 - 7522 (2007/10/03)
A new and general method has been developed for preparation of coumarins and quinolinones by intramolecular hydroarylation of alkynes. Various aryl alkynoates and alkynanilides undergo fast intramolecular reaction at room temperature in the presence of a
