The Pd(OAc)2/PhI(OAc)2 catalyst system promotes the highly regioselective dehydrogenative methoxylation of a C(sp3)–H bond adjacent to benzoxazole and benzothiazole rings. The title transformation constitutes the first example of a Pd-catalyzed C(sp3)–H activating methoxylation at the proximal-selective α-position with regard to a directing auxiliary and provides expedient access to an important class
Pd(OAc)2 / PhI(OAc)2催化剂体系促进与
苯并恶唑和
苯并噻唑环相邻的C(sp 3)–H键的高区域选择性脱氢甲氧基化。标题转换构成了Pd催化的C(sp 3)-H在定向辅助剂的近端选择性α位置上激活甲氧基化的第一个例子,并提供了方便的途径来访问重要的一类由唑修饰的甲基醚(高达90%的分离产率)。通过消除
苯并恶唑助剂获得α-
甲氧基乙酸,并获得O-甲基化Breslow中间体的前体,证明了该方法的合成实用性。