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.
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
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.
A simple Lewis acid induced reaction of phenols with electrophiles: Synthesis of functionalized 4<i>H</i>-chromenes and <i>ortho</i>-benzylphenols
作者:Chinnabattigalla Sreenivasulu、Ditto Abraham Thadathil、Sumit Pal、Satyanarayana Gedu
DOI:10.1080/00397911.2019.1689268
日期:2020.1.2
Abstract Lewisacid ZnCl2 promoted cyclization protocol to 4H-chromenes is accomplished, using readily available phenols and acetophenones as starting materials. Interestingly, the process is feasible under the solvent free environment. Synthesis of a variety of 4H-chromenes have been accomplished using this strategy. In addition, this concept is extended to the synthesis of ortho-benzylphenols by