Synthesis of <i>gem</i>-Difluoro-3,4-dihydro-2<i>H</i>-pyrans via a TfOH-Catalyzed [4 + 2] Annulation of Difluoroenoxysilanes with α-Cyano Chalcones
作者:Jing Zhang、Daokai Xiong、Zhiwei Jiang、Shuaiting Chen、Guo-Bo Huang、Jinshan Li、Zhiming Wang、Jianguo Yang
DOI:10.1021/acs.orglett.4c00078
日期:2024.2.23
However, its application in the annulation reaction for the construction of fluorinated heterocyclic compounds remains relatively limited. Presented here is the Brønsted acid-catalyzed efficient formal [4 + 2] annulation of difluoroenoxysilanes with α-cyano chalcones. The developed protocol demonstrates tolerance to various substituents under mild reaction conditions, providing a reliable approach to construct
二氟烯氧基硅烷是一种常用的二氟烯氧基化试剂,近年来引起了人们的广泛关注。然而,其在构建氟化杂环化合物的成环反应中的应用仍然相对有限。这里介绍的是二氟烯氧基硅烷与 α-氰基查耳酮在布朗斯台德酸催化下的高效形式 [4 + 2] 成环反应。所开发的方案证明了在温和反应条件下对各种取代基的耐受性,提供了一种可靠的方法来构建宝石-二氟-3,4-二氢-2 H-吡喃,以良好至优异的产率和高非对映选择性。