在良性条件下通过直接自由基-自由基交叉偶联来构建C(sp 3)-N键是一种理想但具有挑战性的方法。在此,通过镍/光氧化还原双重催化,以简明,温和且无氧化剂的方式将烷基和and基自由基交叉偶联以建立脂族C–N键。在该协议中,成功地采用了单电子转移策略,分别从磺酰基叠氮化物/叠氮基甲酸酯和烷基三氟硼酸酯生成N-和C-中心的自由基。然而,光催化剂诱导的三重态-三重态能量转移机制可能不适用于该反应。激发的光催化剂(Ru II / * Ru II / Ru III / Ru II的氧化猝灭途径))结合可能的Ni I / Ni II / Ni III / Ni I催化循环,基于协同实验和计算研究,提出了镍/光氧化还原双催化C(sp 3)–N键形成的方法。
The catalyticC(sp3)-H functionalization is highly desirable yet challenging in organic synthesis. Incorporation of the SP(O)(OR)2 group through C(sp3)-H functionalization remains unexplored. We herein report an unprecedented protocol for phosphorothiolation of primary and secondary C(sp3)-H via a multicomponent reaction with N-fluoro-substituted amides, elemental sulfur, and P(O)H compounds involving
Copper‐Catalyzed Remote C(sp
<sup>3</sup>
)−H Trifluoromethylation of Carboxamides and Sulfonamides
作者:Zhonglin Liu、Haiwen Xiao、Benxiang Zhang、Haigen Shen、Lin Zhu、Chaozhong Li
DOI:10.1002/anie.201813425
日期:2019.2.18
catalyst, the reaction of N‐fluoro‐substituted carboxamides (or sulfonamides) with Zn(CF3)2 complexes provides the corresponding δ‐trifluoromethylated carboxamides (or sulfonamides) in satisfactory yields under mild reaction conditions. A radical mechanism involving 1,5‐hydrogen atom transfer of N‐radicals followed by CF3‐transfer from CuII−CF3 complexes to the thus formed alkyl radicals is proposed.
本文报道的是未活化的脂族C(sp 3)-H键的三氟甲基化的空前协议。以Cu(OTf)2为催化剂,N-氟取代的羧酰胺(或磺酰胺)与Zn(CF 3)2配合物的反应在温和的反应条件下以令人满意的收率提供了相应的δ-三氟甲基化的羧酰胺(或磺酰胺)。提出了一种自由基机理,涉及N自由基的1,5-氢原子转移,然后从Cu II -CF 3络合物向如此形成的烷基自由基进行CF 3-转移。
作者:Xia Hu、Guoting Zhang、Faxiang Bu、Lei Nie、Aiwen Lei
DOI:10.1021/acscatal.8b02847
日期:2018.10.5
The cross-coupling of C(sp3)–H and N–H represents one of the most straightforward approaches to construct saturated nitrogen-containing compounds. The additional oxidants or halogenated reagents are generally required in such processes. Herein, we developed an electrochemical oxidative intramolecularC(sp3)–Hamination of amides by employing a carbon rod anode and a platinum plate cathode in an undivided