Iron Catalyzed Double Bond Isomerization: Evidence for an Fe
<sup>I</sup>
/Fe
<sup>III</sup>
Catalytic Cycle
作者:Callum R. Woof、Derek J. Durand、Natalie Fey、Emma Richards、Ruth L. Webster
DOI:10.1002/chem.202004980
日期:2021.4
Density Functional Theory (DFT) and Electron Paramagnetic Resonance (EPR) spectroscopy. The data obtained support a pre‐catalyst activation step that gives access to an η2‐coordinated alkene FeI complex, followed by oxidative addition of the alkene to give an FeIII intermediate, which then undergoes reductive elimination to allow release of the isomerization product.
据报道,铁催化的烯烃异构化使用铁(II) β-二酮亚胺预催化剂。该反应在催化量的氢化物源(例如频哪醇硼烷(HBpin)或氨硼烷(H 3 N·BH 3))下进行。已研究了与烯丙基芳烃和脂肪族烯烃的反应性。通过多种手段研究了催化机理,包括氘化研究、密度泛函理论(DFT)和电子顺磁共振(EPR)光谱。获得的数据支持预催化剂活化步骤,该步骤提供了 η 2配位烯烃 Fe I络合物,然后通过氧化加成烯烃得到 Fe III中间体,然后进行还原消除以释放异构化产物。
Photooxidizing Chromium Catalysts for Promoting Radical Cation Cycloadditions
作者:Susan M. Stevenson、Matthew P. Shores、Eric M. Ferreira
DOI:10.1002/anie.201501220
日期:2015.5.26
The photooxidizing capabilities of selected CrIII complexes for promotingradicalcationcycloadditions are described. These complexes have sufficiently long‐lived excited states to oxidize electron‐rich alkenes, thereby initiating [4+2] processes. These metal species augment the spectrum of catalysts explored in photoredox systems, as they feature unique properties that can result in differential
A facile and convenient sequential homobimetallic catalytic approach towards β-methylstyrenes. A one-pot Stille cross-coupling/isomerization strategy
作者:Sebastián O. Simonetti、Enrique L. Larghi、Teodoro S. Kaufman
DOI:10.1039/c4ob00604f
日期:——
A one-pot approach towards β-methylstyrenes is reported. The transformation involves a Stille cross-coupling reaction of aryl halides with allyltributylstannane, followed by an in situ Pd-catalyzed double bond conjugative migration.
Development of a polymer bound Wittig reaction and use in multi-step organic synthesis for the overall conversion of alcohols to β-hydroxyamines
作者:Martin H. Bolli、Steven V. Ley
DOI:10.1039/a803612h
日期:——
An efficient combinatorial access to β-hydroxyamines suitable for automation is achieved by the mild oxidation of alcohols to aldehydes by polymer supported perruthenate (PSP), the subsequent clean olefination of the obtained aldehydes by polymer supported Wittig reagents followed by the epoxidation of the olefins by dimethyldioxirane (DMDO), and the final aminolysis of the epoxides with various amines is described.
Photocatalytic Synthesis of Dihydrobenzofurans by Oxidative [3+2] Cycloaddition of Phenols
作者:Travis R. Blum、Ye Zhu、Sarah A. Nordeen、Tehshik P. Yoon
DOI:10.1002/anie.201406393
日期:2014.10.6
We report a protocol for oxidative [3+2] cycloadditions of phenols and alkenesapplicable to the modular synthesis of a large family of dihydrobenzofuran natural products. Visible‐light‐activated transition metal photocatalysis enables the use of ammonium persulfate as an easily handled, benign terminal oxidant. The broad range of organic substrates that are readily oxidized by photoredox catalysis