已经开发了钯催化的好氧氧化C–H硝化和芳烃与简单易用的亚硝酸叔丁酯(TBN)和甲苯作为自由基前体的酰化反应。分子氧被用作末端氧化剂和氧源以引发活性自由基反应物。在这些新颖的转化中可以使用许多不同的导向基团,例如吡啶,嘧啶,吡唑,吡啶醇,吡啶基酮,肟和偶氮基团。通过自由基过程的Pd II / Pd IV催化循环是这些氧化的CH–H硝化和酰化反应的最可能途径。
Copper-Mediated Chelation-Assisted <i>Ortho</i> Nitration of (Hetero)arenes
作者:Lin Zhang、Zhenhua Liu、Huiqin Li、Guichun Fang、Badru-Deen Barry、Tuemay Abadi Belay、Xihe Bi、Qun Liu
DOI:10.1021/ol2028288
日期:2011.12.16
A novel copper-mediated chelation-assisted ortho C–H nitration of (hetero)arenes has been developed for the first time, which used dioxygen as terminal oxidant and 1,2,3-TCP as solvent, leading to the synthesis of nitroaromatics with excellent regioselectivity and in good yields. Mechanistic investigations indicate a mechanism involving a four-centered transition state, with simultaneous cleavage of