钴催化双齿导向基辅助的1-萘胺衍生物与醇的区域选择性碳氢键烷氧基化反应

研究了吡啶酰胺双齿导向的钴催化1-萘胺衍生物的区域选择性碳氢键烷氧基化反应.研究发现不仅一元醇可以作为烷氧化剂在标准条件下较好地实现1-萘胺C(8)位的烷氧化反应,而且具有多重用途的脂肪二元醇以及低聚乙二醇,也可以以中等的收率得到相应的目标化合物,这可能是钴催化碳氢键活化构筑碳氧键的首次发现.此外,利用这个实验方法,以氘代甲醇为烷氧化试剂实现了同位素标记的8-烷氧基取代的1-萘胺衍生物的合成.通过控制实验,发现该反应中吡啶酰基是最佳的双导向基团,而且反应过程可能经历了单电子转移机理.

Cobalt-Catalyzed Bidentate-Assisted Regioselective C—H Alkoxylation of 1-Naphthylamide with Alcohols

The cobalt-catalyzed regioselective C—H alkoxylation of 1-naphthylamide with alcohols through a bidentate-chelation assistance has been developed.In this transformation,not only primary and secondary alcohols,but also aliphatic diols and oligoethylene glycols,which always be employed as O,O-donor ligands and reducing agents in transition metal catalyzed coupling reaction,were all tolerated under current reaction conditions.It is noteworthy that deuterium labeled 8-alkoxyl-l-N-(naphthalen-l-yl)picolinamide derivative was easily achieved under this catalytic system.In addition,control experiments suggested that picolinoyl was the key directing group,and furthermore,the C(8)—H alkoxylation reaction might proceed through a single-electron-transfer(SET)process.