1070-40-2Relevant academic research and scientific papers
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
, p. 8155 - 8168 (2016)
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.
Some special features of hydroalumination-iodination of alkyne-1,4-diols
Gharibyan,Makaryan,Hovhannisyan,Kinoyan,Chobanyan
, p. 457 - 464 (2014/05/20)
Hydroalumination-iodination of alkyne-1,4-diols of different structure showed that with increasing number of substituents at the C-OH group the amount of β-iodo-substituted products with respect to this group increased. In the case of symmetric secondary 1,4-diols the reaction results in a 1: 1 mixture of stereoisomeric iodoalkenediols, and in the case of phenyl substituents the reaction proceeds regio- and stereoselectively to give an alkenediol iodine atom in the β-position to phenyl group.
Highly Stereoselective approach to Alk-2-yne-1,4-diols by oxazaborolidine-mediated reduction of Alk-2-yne-1,4-diones
Ariza, Xavier,Bach, Jordi,Berenguer, Ramon,Farras, Jaume,Fontes, Montserrat,Garcia, Jordi,Lopez, Marta,Ortiz, Jordi
, p. 5307 - 5313 (2007/10/03)
We performed the borane-mediated reduction of a series of symmetrical alk-2-yne-1,4-diones (5) in the presence of the oxazaborolidine (R)-6 to afford (R,R)-alk-2-yne-1,4-diols ((R,R)-1) in good yields and high stereoselectivities (up to 99.9% ee). In some cases, the stereochemical purity of 1 was improved by a two-step process: (i) temporary transformation of 1 into its vic-dibromo derivatives 9, which allowed us to remove the minor meso isomer by chromatography, and (ii) regeneration of the enantioenriched diols 1 with SmI2. Reduction of the hexacarbonyldicobalt complexes 8 derived from 5 was also successful.
