Electronically Mismatched Cycloaddition Reactions via First-Row Transition Metal, Iron(III)–Polypyridyl Complex
作者:Jung Ha Shin、Eun Young Seong、Hyeon Jin Mun、Yu Jeong Jang、Eun Joo Kang
DOI:10.1021/acs.orglett.8b02541
日期:2018.9.21
one-electron oxidant, producing radicalcations from olefins and promoting the efficient radicalcation [2 + 2] and [2 + 4] cycloaddition reactions. Subsequent chain propagation afforded trisubstituted cyclobutane or cyclohexene derivatives, and this facile route enables the replacement of rare metals with sustainable, green, and inexpensive iron in radicalcationcycloadditions.
Iron(III) perchlorate catalyzed cyclodimerization of trans-anethole gave trans,anti,trans-cyclobutane stereospecifically in good yield. Alumina supported iron(III) perchlorate was an especially efficient one-electron oxidation reagent.
Investigating radical cation chain processes in the electrocatalytic Diels–Alder reaction
作者:Yasushi Imada、Yohei Okada、Kazuhiro Chiba
DOI:10.3762/bjoc.14.51
日期:——
Single electron transfer (SET)-triggered radical ion-based reactions have proven to be powerful options in synthetic organic chemistry. Although unique chain processes have been proposed in various photo- and electrochemical radical ion-based transformations, the turnover number, also referred to as catalytic efficiency, remains unclear in most cases. Herein, we disclose our investigations of radical
Visible-Light-Irradiated Graphitic Carbon Nitride Photocatalyzed Diels-Alder Reactions with Dioxygen as Sustainable Mediator for Photoinduced Electrons
作者:Yubao Zhao、Markus Antonietti
DOI:10.1002/anie.201703438
日期:2017.8.1
photoredox system. Moreover, the reactionintermediate vinylcyclobutane is captured and monitored during the reaction, serving as a direct evidence for the proposed reaction mechanism. The cycloaddition process is thereby determined to be the combination of direct [4+2] cycloaddition and [2+2] cycloaddition followed by photocatalytic rearrangement of the vinylcyclobutane intermediate.
石墨碳氮化物(g-C 3 N 4)在可见光辐射和有氧条件下,与富电子烯烃的光催化Diels-Alder(D-A)反应得以实现。这种异质的光氧化还原反应系统非常高效,模型反应的表观量子产率达到了47%的显着值。双氧作为电子介体起着至关重要的作用,这与先前有关均相Ru II的报道不同复杂的光氧化还原系统。此外,在反应过程中捕获并监测了反应中间体乙烯基环丁烷,为提出的反应机理提供了直接证据。从而将环加成过程确定为直接的[4 + 2]环加成和[2 + 2]环加成,然后进行乙烯基环丁烷中间体的光催化重排的组合。
Host–Guest-Induced Electron Transfer Triggers Radical-Cation Catalysis
作者:Rebecca L. Spicer、Athanasios D. Stergiou、Tom A. Young、Fernanda Duarte、Mark D. Symes、Paul J. Lusby
DOI:10.1021/jacs.9b11273
日期:2020.2.5
principle of capsule catalysis. Here we show an alternative strategy, wherein catalytic activation of otherwise inactive quinone "co-factors" by a simple Pd2L4 capsule pro-motes a range of bulk-phase, radical-cation cycloadditions. Solution electron transfer experiments and cyclic voltammetry show the cage anodically shifts the redox potential of the encapsulated quinone by a significant 1 V. Moreover, the