Synthesis of acetylpyrazines 3 and propionylpyrazines 5 was achieved by copper-cocatalytic Stille reaction of bromopyrazines 1 with tributyl(1-ethoxyalkenyl)tin and then acidic hydrolysis. The optimal reaction conditions involve the combination of 15 mol% CuI with 5 mol% of PdCl2(Ph3P)2. Similarly, 2-acylpyridines and propionylbenzenes were prepared from the corresponding aryl bromides.
溴吡嗪1与三丁基(1-乙氧基烯基)
锡通过
铜共催化Stille反应,然后酸
水解合成乙酰
吡嗪3和丙酰
吡嗪5。最佳反应条件为 15 mol% CuI 与 5 mol% PdCl2(Ph3P)2 的组合。类似地,由相应的芳基
溴制备2-酰基
吡啶和丙酰苯。