An efficient and rapid method is described for the reductive Claisen rearrangement of different propargyloxyanthraquinones to anthra[1,2-b]furan-6,11-diones for first time using iron powder in a mixture of two ionic liquids, namely 1-methylimidazolium tetrafluoroborate [Hmim]BF4 and 1-benzyl-3-methylimidazolium chloride [Bzmim]Cl. The present method is able to execute single or double Claisen rearrangements of 1,4- or 1,5-bispropargyloxyanthraquinones selectively, so that the desired anthra(mono)furandiones or anthra(bis)furandiones are produced, respectively, as the major product.
本文描述了一种高效快速的方法,使用
铁粉在两种
离子液体混合物中,即1-甲基
咪唑四
氟硼酸盐[Hmim]BF
4和1-苄基-3-甲基
咪唑氯化物[Bzmim]Cl,首次对不同的
丙炔氧基
蒽醌进行还原的克莱仙重排反应,生成
蒽[1,2-b]
呋喃-6,11-二酮。该方法能够选择性地执行1,4-或1,5-双
丙炔氧基
蒽醌的单次或双次克莱仙重排反应,从而分别产生所需的
蒽(单)
呋喃二酮或
蒽(双)
呋喃二酮作为主要产物。