氧气作为唯一氧化剂的钯催化咖啡因或尿嘧啶C—H键直接芳基化反应

Palladium-Catalyzed C—H Direct Arylation of Uracils and Caffeines with Arenes Using Molecular Oxygen as the Sole Oxidant

报道了钯催化咖啡因或尿嘧啶C—H与芳烃C—H的脱氢偶联反应.反应最大特点是采用常压氧气作为唯一氧化剂.反应对很多官能团,比如卤素、酯基、硝基、腈基、醚等,都有很好的容忍度.本方法为制备C6-芳基尿嘧啶或C8-芳基咖啡因衍生物提供了简便、直接和绿色经济路线.

Palladium-catalyzed cross-dehydrogenative coupling of uracil or caffeine with unactivated arenes has been devel- oped. The approach was characterized by using atmospheric pressure of molecular oxygen as the sole oxidant. Functional groups such as halo, ester, nitro, nitrile and ether are well-tolerated under the reaction conditions. This novel strategy provides a straightforward, facile and economical route to C6-aryl uracil derivatives or CS-arvl caffeine derivatives.