wide variety of functional groups. Reported herein is a direct method for the highly regioselective preparation of 5-membered and 7-membered cyclic ketals in respectable to good yields from aryl bromides (1a–k) and electron-rich olefins (2a and b). The reaction is performed with palladium catalysis using ionic liquid as solvent with no need for any halide scavengers, providing an alternative to the
                                    Heck反应包括有机合成中最重要的碳-碳偶联反应之一。该反应的普及归因于芳基卤化物的广泛可获得性以及该反应对多种官能团的耐受性。本文报道的是一种高区域选择性制备5元和7元环状
缩酮的直接方法,可从芳基
溴化物(1a-k)和富含电子的烯烃(2a和b)中获得良好的产率。该反应通过使用
离子液体作为溶剂的
钯催化进行,不需要任何卤化物清除剂,为使用芳基
三氟甲磺酸酯提供了另一种选择。发现
离子液体可通过以下途径将反应路径引向专有的α-芳基化 阳离子路线。