Palladium(II)‐Catalyzed Direct Access to Indeno[1,2‐
<i>c</i>
]isochromen‐5(11
<i>H</i>
)‐Ones via Intramolecular Oxypalladation‐Initiated Cascade Process
作者:Muthu Karuppasamy、B. S. Vachan、Tanvi Jandial、Sesuraj Babiola Annes、Nattamai Bhuvanesh、C. Uma Maheswari、Vellaisamy Sridharan
DOI:10.1002/adsc.202000456
日期:2020.7.16
A palladium(II)‐catalyzed cascade approach was established for the synthesis of indeno[1,2‐c ]isochromen‐5(11H )‐ones starting from 2‐alkynyl tert‐butyl benzoates bearing a pendant α,β‐unsaturated carbonyl moiety in high yields (up to 99%) under mild conditions. This strategy offered high atom and step economy by delivering isobutene as the only side product, and by generating two new bonds and two
建立了钯(II)催化的级联方法,用于合成带有[α,β-不饱和羰基]侧基的2-炔基叔丁基苯甲酸酯,从而合成茚并[1,2 - c ]异色素n-5(11 H)-酮。在温和的条件下以高收率(高达99%)收割。该策略通过提供异丁烯作为唯一的副产物,并在一次合成操作中生成两个新的键和两个环,从而提供了高原子和步进经济性。可以看到级联过程的机理,包括顺序的分子内氧合palpalpalation(6-endo-dig),分子内的烯烃插入和质子化步骤。