1087-09-8Relevant articles and documents
Electrochemical synthesis of 1,2-diketones from alkynes under transition-metal-catalyst-free conditions
Zhou, Jie,Tao, Xiang-Zhang,Dai, Jian-Jun,Li, Chen-Guang,Xu, Jun,Xu, Hong-Mei,Xu, Hua-Jian
supporting information, p. 9208 - 9211 (2019/08/07)
We report an electrochemical protocol for the direct oxidation of internal alkynes in air to provide 1,2-diketones. A variety of functional groups and heterocycle-containing substrates can be tolerated well under mild conditions.
Cycloaddition Reaction of Vinylphenylfurans and Dimethyl Acetylenedicarboxylate to [8 + 2] Isomers via Tandem [4 + 2]/Diradical Alkene-Alkene Coupling/[1,3]-H Shift Reactions: Experimental Exploration and DFT Understanding of Reaction Mechanisms
Chen, Kai,Wu, Feng,Ye, Lijuan,Tian, Zi-You,Yu, Zhi-Xiang,Zhu, Shifa
supporting information, p. 8155 - 8168 (2016/09/28)
An experimental test of designed [8 + 2] reaction of vinylphenylfuran and dimethyl acetylenedicarboxylate (DMAD) has been carried out, showing that the reaction gave unexpected addition products under different conditions. When the reaction was conducted under thermal conditions in toluene, expoxyphenanthrene, which was named as a [8 + 2] isomer, was generated. The scope of this reaction has been investigated in the present study. In addition, experiments and DFT calculations have been conducted to investigate how the reaction between vinylphenylfuran and DMAD took place. Surprisingly, the reaction did not involve the expected [8 + 2] intermediate, o-quinodimethane. Instead, the reaction starts from intermolecular Diels-Alder reactions between DMAD and the furan moiety of vinylphenylfuran, followed by unexpected intramolecular alkene-alkene coupling. This step generates a diradical species, which then undergoes [1,3]-H shift to give the experimentally observed expoxyphenanthrene. DFT calculations revealed that, the [8 + 2] cycloadduct cannot be obtained because the [1,5]-H shift process from the [1,5]-vinyl shift intermediate is disfavored kinetically compared to the [1,3]-H shift to the [8 + 2] isomer.
Catalysis by ionic liquid. A green protocol for the stereoselective debromination of vicinal-dibromides by [pmIm]BF4 under microwave irradiation
Ranu, Brindaban C.,Jana, Ranjan
, p. 8621 - 8624 (2007/10/03)
An easily accessible ionic liquid, 1-methyl-3-pentylimidazolium fluoroborate, [pmIm]BF4, has been demonstrated to be an efficient catalyst as well as reaction medium for the stereoselective debromination of a variety of structurally diverse vicinal-dibromides to the corresponding (E)-alkenes in high yields under microwave irradiation. This reaction does not require any organic solvent and any metal or any conventional reducing agent, and the ionic liquid is recycled without any appreciable loss of its catalytic efficiency.