Convenient and Highly Efficient Routes to 2
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‐Chromene and 4‐Chromanone Derivatives: Iodine‐Promoted and
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‐Toluenesulfonic Acid Catalyzed Cascade Cyclizations of Propynols
A convenient strategy is presented for the easy preparation of a series of 2H‐chromenes under mild conditions through iodocyclization of readily accessible propynols. In addition, various 4‐chromanones can be synthesized through a p‐toluenesulfonicacidcatalyzedcascadecyclization with high efficiency (yields up to 99 %). Our developed reaction systems are proven to have good functional‐group applicability
Direct Exploitation of the Ethynyl Moiety in Calcium Carbide Through Sealed Ball Milling
作者:Abolfazl Hosseini、Peter R. Schreiner
DOI:10.1002/ejoc.202000612
日期:2020.8.2
Sealedballmilling provides a novel way of activation of calciumcarbide. No additive is required to transfer the acetylide moiety to organic molecules. Various ketones and even aryl halides can thereby be ethynylated.