Palladium-Catalyzed Tandem Reactions To Form 1-Vinyl-1<i>H</i>-isochromene Derivatives<sup>1</sup>
作者:Roger Mutter、Ian B. Campbell、Eva M. Martin de la Nava、Andy T. Merritt、Martin Wills
DOI:10.1021/jo0011991
日期:2001.5.1
also an essential choice as it furnishes the appropriate reactivity to promote allylic substitution after the aryl coupling process. The use of more effective leaving groups, such as acetate, results in reaction of the allylic group, and no aryl coupling is observed. Through the appropriate selection of phosphine ligand and solvent, either the cyclized isochromene product or the noncyclized intermediate
松果酮与叔丁基二甲基(3-(2-溴苯基)烯丙氧基)硅烷的钯催化反应可直接形成1-乙烯基-3-叔丁基-1H-异戊烯。这是酮芳基化,然后烯醇与烯丙基体系分子内环化的结果。使用二酰胺锂碱似乎对成功至关重要。叔丁基二甲基甲硅烷基保护基也是必不可少的选择,因为它在芳基偶联过程之后提供适当的反应性来促进烯丙基取代。使用更有效的离去基团,例如乙酸酯,导致烯丙基的反应,并且未观察到芳基偶联。通过膦配体和溶剂,无论是环化的苯并吡喃产物或中间noncyclized的适当选择可以选择性地形成。