Reductive Coupling between C–N and C–O Electrophiles
作者:Rong-De He、Chun-Ling Li、Qiu-Quan Pan、Peng Guo、Xue-Yuan Liu、Xing-Zhong Shu
DOI:10.1021/jacs.9b05224
日期:2019.8.14
The cross-electrophile reaction is a promising strategy for C-C bond formation. Recent studies have focused mainly on reactions with organic halides. Here we report a coupling reaction between C-N and C-O electrophiles that demonstrates the possibility of constructing a C-C bond via C-N and C-O cleavage. Several reactions between benzyl/aryl ammonium salts and vinyl/aryl C-O electrophiles have been
交叉亲电反应是 CC 键形成的一个有前景的策略。最近的研究主要集中在与有机卤化物的反应上。在这里,我们报告了 CN 和 CO 亲电试剂之间的偶联反应,证明了通过 CN 和 CO 裂解构建 CC 键的可能性。已经研究了苄基/芳基铵盐和乙烯基/芳基 CO 亲电试剂之间的几种反应。初步机理研究表明,苄基铵是通过自由基机制活化的。
Radical α-Trifluoromethoxylation of Ketones under Batch and Flow Conditions by Means of Organic Photoredox Catalysis
method for the α-trifluoromethoxylation of ketones is reported. Enol carbonates react with N-trifluoromethoxy-4-cyano-pyridinium, using the photoredox catalyst 4-CzIPN under 456 nm irradiation, affording the α-trifluoromethoxy ketones in ≤50% isolated yield and complete chemoselectivity. As shown by 29 examples, the reaction is general and proceeds very rapidly under batch (1 h) and flow conditions (2 min)
Synthesis of 1,4‐Dicarbonyl Compounds by Visible‐Light‐Mediated Cross‐Coupling Reactions of α‐Chlorocarbonyls and Enol Acetates
作者:Qiang Liu、Rui‐Guo Wang、Hong‐Jian Song、Yu‐Xiu Liu、Qing‐Min Wang
DOI:10.1002/adsc.202000791
日期:2020.10.21
visible‐light‐mediatedradical coupling reactions of α‐chloroketones and enol acetates to afford 1,4‐dicarbonyl compounds, which are important precursors and intermediates in organic synthesis. The reaction involves photoredox‐catalyzed activation of the α‐chloroketone upon photoelectron transfer, carbon–chlorine bond cleavage, and coupling of the resulting radical with the carbon–carbon double bond of the
Formation of δ-Lactones with <i>anti</i>
-Baeyer-Villiger Regiochemistry: Investigations into the Mechanism of the Cerium-Catalyzed Aerobic Coupling of β-Oxoesters with Enol Acetates
The cerium-catalyzed, aerobic coupling of β-oxoesters with enol acetates and dioxygen yields δ-lactones with a 1,4-diketone moiety. In contrast to the Baeyer-Villiger oxidation (BVO), where the higher substituted residue migrates, in this case of an oxidative C-C coupling reaction the less substituted alkyl residue undergoes a 1,2-shift. An endoperoxidic oxycarbenium ion comparable to the Criegee intermediate