58966-08-8Relevant academic research and scientific papers
Saegusa Oxidation of Enol Ethers at Extremely Low Pd-Catalyst Loadings under Ligand-free and Aqueous Conditions: Insight into the Pd(II)/Cu(II)-Catalyst System
Zhu, Quan,Luo, Yunsong,Guo, Yongyan,Zhang, Yushun,Tao, Yunhai
, p. 5463 - 5476 (2021/05/05)
A highly efficient and practical Pd(II)/Cu(OAc)2-catalyst system of Saegusa oxidation, which converts enol ethers to the corresponding enals with a number of diverse substrates at extremely low catalyst loadings (500 mol ppm) under ligand-free and aqueous conditions, is described. Its synthetic utility was demonstrated by large-scale applications of the catalyst system to important nature molecules. This work allows Saegusa oxidation to become a highly practical approach to preparing enals and also suggests new insight into the Pd(II)/Cu(II)-catalyst system for dehydrogenation of carbonyl compounds and decreasing Pd-catalyst loadings.
Photocatalytic Dehydrogenative Cross-Coupling of Alkenes with Alcohols or Azoles without External Oxidant
Yi, Hong,Niu, Linbin,Song, Chunlan,Li, Yiying,Dou, Bowen,Singh, Atul K.,Lei, Aiwen
supporting information, p. 1120 - 1124 (2017/01/18)
Direct cross-coupling between alkenes/R-H or alkenes/RXH is a dream reaction, especially without external oxidants. Inputting energy by photocatalysis and employing a cobalt catalyst as a two-electron acceptor, a direct C?H/X?H cross-coupling with H2evolution has been achieved for C?O and C?N bond formation. A new radical alkenylation using alkene as the redox compound is presented. A wide range of aliphatic alcohols—even long chain alcohols—are tolerated well in this system, providing a new route to multi-substituted enol ether derivatives using simple alkenes. Additionally, this protocol can also be used for N-vinylazole synthesis. Mechanistic insights reveal that the cobalt catalyst oxidizes the photocatalyst to revive the photocatalytic cycle.
Regio- and stereoselective hydrostannation of allenes using dibutyliodotin hydride (Bu2SnIH) and successive coupling with aromatic halides
Hayashi, Naoki,Kusano, Kazunao,Sekizawa, Shingo,Shibata, Ikuya,Yasuda, Makoto,Baba, Akio
, p. 4913 - 4915 (2008/09/18)
Regio- and stereoselective hydrostannation of allenes by using di-n-butyliodotin hydride (Bu2SnIH) was accomplished to give α,β-disubstituted vinyltins, which induced the synthesis of multi-substituted alkenes in a one-pot procedure. The Royal Society of Chemistry.
Thermal and photochemical solvolysis of (E)- and (Z)-2-phenyl-1-propenyl(phenyl)iodonium tetrafluoroborate: Benzenium and primary vinylic cation intermediates
Gronheid,Lodder,Ochiai,Sueda,Okuyama
, p. 8760 - 8765 (2007/10/03)
The thermal and photochemical solvolysis of the two stereoisomeric 2-phenyl-1-propenyl(phenyl)-iodonium tetrafluoroborates has been investigated in alcoholic solvents of varying nucleophilicity. The product profiles and rates of product formation in the thermal reaction are all compatible with a mechanism involving cleavage of the vinylic C - I bond assisted by the group in the trans position (methyl or phenyl), always leading to rearranged products. Depending on the nucleophilicity of the solvent, the primarily formed cations may or may not further rearrange to more stable isomers. The less reactive Z compound also yields some unrearranged vinyl ether product in the more nucleophilic solvents via an in-plane SN2 mechanism. The mechanism of the photolysis involves direct, unassisted cleavage of the vinylic, and aromatic, C - I bond in an SN1 mechanism. This produces a primary vinyl cation, which is partially trapped prior to rearrangement in methanol. The unrearranged vinyl ethers are mainly formed with retention of configuration via a λ3-iodonium/solvent complex in an SNi mechanism. Thermal and photochemical solvolyses of iodonium salts are complementary techniques for the generation of different cation intermediates from the same substrate.
