Highly Regioselective Palladium-Catalyzed Direct Arylation of Oxazole at C-2 or C-5 with Aryl Bromides, Chlorides, and Triflates
作者:Neil A. Strotman、Harry R. Chobanian、Yan Guo、Jiafang He、Jonathan E. Wilson
DOI:10.1021/ol1011778
日期:2010.8.20
Complementary palladium-catalyzed methods for direct arylation of oxazole with high regioselectivity (>100:1) at both C-5 and C-2 have been developed for a wide range of aryl and heteroaryl bromides, chlorides, iodides, and triflates. C-5 arylation is preferred in polar solvents with phosphines 5 or 6, whereas C-2 arylation is preferred by nonpolar solvents and phosphine 3. This represents the first
已经开发了在钯C-5和C-2上具有高区域选择性(> 100:1)的芳基直接芳基化的互补钯催化方法,适用于各种芳基和杂芳基溴化物,氯化物,碘化物和三氟甲磺酸酯。在带有膦5或6的极性溶剂中,C-5芳基化是优选的,而在非极性溶剂和膦3中,C-2芳基化是优选的。生物活性分子的合成。此外,在机械观测的基础上,提出了这两个相互竞争的芳基化过程的潜在机制。