Gold-Catalyzed Hydrative Carbocyclization of 1,5- and 1,6-Diyn-3-ones via an Oxygen Transfer Process
摘要:
This study reports new hydrative carbocyclizations of 1,5- and 1,6-diyn-3-ones catalyzed by PPh3AuOTf, involving a pi-alkyne-assisted oxygen transfer in the reaction mechanisms. Treatment of 2-(alk-2-yn-1-onyl)-1-alkynylbenzenes with PPh3AuOTf (5 mol %) in wet 1,4-dioxane (23 degrees C, 10 min) led to hydrative aromatization to give 4-hydroxyl-1-naphthyl ketones efficiently. This approach is also extendible to the hydrative cyclization of acyclic 1,5-diyn-3-ones, which afforded 4-cyclopentenonyl ketones in reasonable yields. On the basis of this oxygen-labeling study, we propose a plausible mechanism involving an alkyne-assisted oxygen transfer to generate key oxonium and gold-enolate intermediates.
Synthesis of Polysubstituted Naphthofurans and Indenofurans Based on a Regiodivergent Intramolecular Carbometalation Strategy with 2‐(2’‐Alkynylaryl)‐3‐iodofurans
作者:Azusa Kondoh、Kohei Aita、Masahiro Terada
DOI:10.1002/chem.202300132
日期:——
Efficient methods for the synthesis of two types of furan-fused tricyclic compounds were developed based on a regiodivergent intramolecular carbometalation strategy using 2-(2’-alkynylaryl)-3-iodofurans as a common substrate. The methods involving the 6-endo-anti carbocupration or the formal intramolecular 5-exo-anti carbopalladation provide new access to a wide range of well-organized polysubstituted
基于使用 2-(2'-炔基芳基)-3-碘呋喃作为常见底物的区域发散分子内碳金属化策略,开发了两种类型的呋喃稠合三环化合物的有效合成方法。涉及 6-endo- anti carbocupration 或正式分子内 5-exo- anti carbopalladation的方法为广泛的组织良好的多取代萘并[1,2- b ]呋喃和茚并[1,2- b ]提供了新途径否则难以获得的呋喃。