Experimental and Computational Investigations of the Reactions between α,β‐Unsaturated Lactones and 1,3‐Dienes by Cooperative Lewis Acid/Brønsted Acid Catalysis
作者:Anja Weber、Martin Breugst、Jörg Pietruszka
DOI:10.1002/ange.202008365
日期:2020.10.12
AbstractThe reactions of α,β‐unsaturated δ‐lactones with activated dienes such as 1,3‐dimethoxy‐1‐[(trimethylsilyl)oxy]‐1,3‐butadiene (Brassard's diene) are barely known in literature and show high potential for the synthesis of isocoumarin moieties. An in‐depth investigation of this reaction proved a stepwise mechanism via the vinylogous Michael‐products. Subsequent cyclisation and oxidation by LHMDS
摘要α,β-不饱和δ-内酯与活化二烯如1,3-二甲氧基-1-[(三甲基硅基)氧基]-1,3-丁二烯(布拉萨二烯)的反应在文献中鲜为人知,并且显示出很高的潜力异香豆素部分的合成。对该反应的深入研究证明了通过插烯迈克尔产物的逐步机制。随后通过 LHMDS 和 DDQ 进行环化和氧化,通过三个步骤分别提供了六种 Mellein 衍生物 (30-84%) 和四种当归碱衍生物 (40-78%)。DFT 计算提供了对反应机理的深入了解并支持逐步反应理论。