A powerful approach to alkoxy radical-mediated remote C(sp3)-H bonds functionalization

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2018,（5）
• 页码范围: 505-506
• 页数: 2页
• 语种: 英文

摘要

The activation of inert C(sp3)-H bonds with control of reactivity and selectivity is one of the central topics in chemical sciences.In this context,alkoxy radical-mediated 1,5-hydrogen atom transfer allows the regioselective transformation of inert C(sp3)-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].