p -Toluenesulfonic acid-catalyzed metal-free formal [4 + 1] heteroannulation via N H/O H/S H functionalization: One-pot access to 2-aryl/hetaryl/alkyl benzazole derivatives
concise and direct one-pot [4 + 1] synthetic strategy for the construction of 2-substituted benzazoles such as benzoxazoles and benzothiazoles has been disclosed in high yields (80–98%) by cascade coupling reaction of 2-amino(thio)phenols with β-oxodithioesters. The current approach enables NH/OH/SH functionalization in one-pot under solventless condition leading to diverse benzazoles without use of any
通过2-氨基(硫代)的级联偶联反应,已公开了一种高产率(80-98%)的简洁,直接的一锅[4 +1]合成策略,用于构建2-取代的苯并唑,如苯并恶唑和苯并噻唑酚与β-氧二硫代酯。目前的方法可以在无溶剂条件下在一锅中实现N H / O H / S H官能化,从而无需使用任何外部金属即可产生多种苯并恶唑。各种各样的2-氨基(硫代)酚和β-氧二硫代酯均具有出色的官能团耐受性,可用于该转化。此外,我们通过证明其与DNA拓扑异构酶II抑制剂的多样化多样化的相容性,抢占了这一新策略的广泛含义。
De Meo; Pedini; Ricci, Il Farmaco, 1989, vol. 44, # 5, p. 475 - 482