A highly effective cascade process giving 3-alkenylcoumarins is furnished by a series of reactions involving pallada-arylation of ethylpropiolate with phenols, intramolecular transesterification t...
Gold(I)-Catalyzed Intramolecular Hydroarylation of Phenol-Derived Propiolates and Certain Related Ethers as a Route to Selectively Functionalized Coumarins and 2<i>H</i>-Chromenes
作者:Aymeric Cervi、Yen Vo、Christina L. L. Chai、Martin G. Banwell、Ping Lan、Anthony C. Willis
DOI:10.1021/acs.joc.0c02011
日期:2021.1.1
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 naturalproducts such as ayapin (144) and scoparone (145) have been realized by such means, and the first of these subject to single-crystal
The First Synthesis of Natural Occurring Juncaceae Coumarin, 9-Hydroxy-8-methyl-3H-benzo[f]chromen-3-one, Featuring a One-pot Rearrangement and Aromatization Cascade
The synthesis of benzocoumarins from β‐tetralones has been achieved via two pathways in the first total synthesis of the Juncaceaenatural product, 9‐hydroxy‐8‐methyl‐3H‐benzo[f]chromen‐3‐one, featuring a one‐pot rearrangement and aromatizationcascade.
Brønsted Acid Catalyzed Direct Annulation of Alkoxyallenes and Naphthols to Chroman Ketals
作者:Cong Zhang、Gaoxi Jiang、Maosheng He、Jinlong Zhang、Hao-Yang Wang
DOI:10.1055/s-0040-1719892
日期:2022.5
acid-catalyzed and scalable annulation of alkoxyallenes with simple naphthols was developed, affording chroman ketals in 49–84% yields. The versatile chroman ketals can be easily converted into coumarins by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-mediated oxidation, and a series of 2-substituted chromans via nucleophilic substitutions.
Synthesis of π‐Expanded Coumarins by Ligand‐Enabled Selective C−H Functionalization
作者:Peng Ren、Zhijie He、Tiantian Xing、Krishna K. Manar、Jessica Sampson、Jian Jin、Long Wang、Brad P. Carrow
DOI:10.1002/adsc.202200468
日期:2022.9.20
a palladium catalyst. The use of an anionic thioether ligand is critical for ensuring the high reactivity of this reaction; it enables low catalyst loadings, mild reaction conditions, and the use of aceticacid as a green solvent. This chemistry is widely applicable to naphthol-based aromaticsubstrates bearing either electron-donating or -withdrawing functional groups.