Aromaticity-Dependent Regioselectivity in Pd(II)-Catalyzed C–H Direct Arylation of Aryl Ureas
作者:Pingping Jiang、Feng Li、Yongbao Xu、Qingwen Liu、Jing Wang、Hong Ding、Renfu Yu、Qifeng Wang
DOI:10.1021/acs.orglett.5b03153
日期:2015.12.4
Palladium-catalyzed C–H direct arylation generally occurs on the ortho-position of directing groups. By comparing meta-arylated products of 2-naphthyl urea to ortho-arylated products of phenyl urea, the ortho- and meta-regioselectivity of aryl ureas were found to depend on the aromaticity of the corresponding aryl substituents. Thus, aromaticity is a new factor which can affect the regioselectivity
钯催化的C–H直接芳基化通常发生在导向基团的邻位。通过比较元2-萘基脲的-arylated产品邻-苯基脲的芳基化产品,邻-和间-芳基脲的区域选择性被发现依赖于相应的芳基的取代基的芳香性。因此,芳香性是一个新的因素,可以影响C–H直接芳基化中的区域选择性。吲哚和吡咯衍生物的区域选择性直接芳基化进一步证实了这一发现。