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
Enantioselective Copper-Catalyzed Remote C(sp<sup>3</sup>)–H Alkynylation of Linear Primary Sulfonamides
作者:Cheng-Yu Wang、Zi-Yang Qin、Yu-Ling Huang、Yi-Ming Hou、Ruo-Xing Jin、Chao Li、Xi-Sheng Wang
DOI:10.1021/acs.orglett.0c01325
日期:2020.5.15
The highly efficient copper-catalyzed enantioselective alkynylation of the remote C(sp3)-H bond on linear primary sulfonamides is presented here using a radical relay strategy. The chiral box-copper complex, which is used to recapture the in-situ-generated alkyl radical via a 1,5-HAT strategy, is the key to success, affording the chiral alkynes after a following reductive elimination. A general substrate
Nickel/Photoredox Dual Catalytic Cross-Coupling of Alkyl and Amidyl Radicals to Construct C(sp<sup>3</sup>)–N Bonds
作者:Shaofang Zhou、Kang Lv、Rui Fu、Changlei Zhu、Xiaoguang Bao
DOI:10.1021/acscatal.1c00731
日期:2021.5.7
The construction of C(sp3)–N bonds via direct radical–radical cross-coupling under benign conditions is a desirable but challenging approach. Herein, the cross-coupling of alkyl and amidyl radicals to build aliphatic C–N bonds in a concise, mild, and oxidant-free manner is implemented by nickel/photoredox dual catalysis. In this protocol, the single electron transfer strategy is successfully employed
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。
Transition‐Metal‐Free α Csp
<sup>3</sup>
−H Cyanation of Sulfonamides
site‐selective α‐functionalization of sulfonylamide derivatives through the in‐situ generation of imine intermediates. The N−F sulfonylamides, which could facilitate the elimination to generate imines, are coupled with TBACN to efficiently and mildly afford α‐amino cyanides. Comparing with Strecker reaction, this transformation offers a complementary strategy to efficiently construct α‐amino cyanides