LAUSR

The activation of inert C(sp)–H bonds with control of reactivity and selectivity is one of the central topics in chemical sciences. In this context, alkoxy radical-mediated 1,5hydrogen atom transfer allows the regioselective transformation of inert C(sp)–H bonds to access functionalized molecules which would otherwise be inaccessible. Although some preliminary but elegant results have been disclosed, this chemistry remains challenging and largely underexploited for the following reasons: (1) the bond dissociation energy of O–H bonds is quite high (105 kcal/mol), and therefore the direct formation of alkoxy radicals from alcohols is truly difficult; and (2) the transient alkoxy radicals are too reactive to harness in many cases. Accordingly, various prefunctionalized precursors (e.g., peroxy compounds, nitrite esters, hypohalites, N-alkoxylpyridine-2-thiones, N-alkoxyphthalimides, etc.) are usually employed to generate alkoxy radicals. Despite advances, the development of catalytic approaches for the straightforward conversion of alcohols to alkoxy radicals under mild and environmentally friendly are highly desirable [1]. Very recently, Zhu and coworkers [2] have elegantly disclosed an efficient tertiary alcohol-guided heteroarylation of remote C(sp)–H bond for the first time (Figure 1). They achieved the mild generation of alkoxy radical from alcoholic O–H bond under visible-light photocatalysis that triggered the subsequent continuous 1,5(6)-migration of hydrogen atom and heteroaryl group. The protocol proved to be general with regard to the scope of tertiary alcohols. Many sensitive groups can be tolerated in the reaction. In addition to benzothiazoles, other N-containing heteroaryls such as thiazole and pyridine also readily migrated to the δ-position. The reaction afforded a variety of valuable remote heteroaryl-substitued ketones. Because benzothiazolyl group is usually treated as “masked carbonyl” in synthetic chemistry and can be easily converted to formyl group, the current method can be regarded as a formal C(sp)–H bond for-