Sulfuric-acid-promoted tandem reaction of phenols with acetophenones under solvent- and metal-free conditions has been developed, which afforded functional 4H-chromenes in good yields with water as the side product.
An efficient and highlyselective approach for the synthesis of functionalized 4H-chromenes has been developed via gold(III)-catalyzed condensation/annulation tandem reaction of ketones with phenols.
Efficient Synthesis of Functionalized 4H-Chromenes via an Fe(OTf)3-Catalyzed Cyclization Reaction of Phenols and Ketones
作者:Hui-Jing Li、Yan-Chao Wu、Kai Deng、Qi-Yong Huai、Jun-Hu Wang、Hui-Ru Yang、Ying Liu
DOI:10.1055/s-0036-1591021
日期:2018.4
Abstract The iron(III) triflate catalyzed cyclization reaction of phenols and ketones is described; the reaction provides a direct approach to 4H-chromene derivatives. 4H-Chromene is an important structural fragment of many pharmaceuticals, natural products, and functional materials. The 4H-chromene synthetic protocol possesses many advantages, such as using readily available and inexpensive starting