80025-09-8Relevant academic research and scientific papers
Somophilic alkynylation of unreactive alkenes enabled by iron-catalyzed hydrogen atom transfer
Ma, Mengtao,Shi, Zhuangzhi,Zhao, Binlin,Zhu, Tianxiang
, (2021/12/29)
We report an efficient and practical iron-catalyzed hydrogen atom transfer protocol for assembling acetylenic motifs into functional alkenes. Diversities of internal alkynes could be obtained from readily available alkenes and acetylenic sulfones with exc
Visible Light-Enabled sp3-C?H Functionalization with Chloro- and Bromoalkynes: Chemoselective Route to Vinylchlorides or Alkynes
Adak, Tapas,Hoffmann, Marvin,Witzel, Sina,Rudolph, Matthias,Dreuw, Andreas,Hashmi, A. Stephen K.
supporting information, p. 15573 - 15580 (2020/10/19)
An unprecedented direct atom-economic chemo- and regioselective hydroalkylation of chloroalkynes and an sp3-C?H alkynylation of bromoalkynes was achieved. The reaction partners are unfunctionalized ethers, alcohols, amides, and even non-activated hydrocarbons. We found that a household fluorescent bulb was able to excite a diaryl ketone, which then selectively abstracts a H-atom from an sp3-C?H bond. The product of a formal alkyne insertion into the sp3-C?H bond was obtained with chloroalkynes, providing valuable vinyl chlorides. The photo-organocatalytic hydrogen atom transfer strategy gives rise to a broad range of diversely functionalized olefins. When bromoalkynes are applied in the presence of a base, a chemoselectivity switch to an alkynylation is observed. This reaction can even be performed for the alkynylation of unactivated sp3-C?H bonds, in this case with a preference of the more substituted carbon. Accompanying quantum chemical calculations indicate a vinyl radical intermediate with pronounced linear coordination of the carbon radical center, thus enabling the formation of both diastereoisomers after H-atom abstraction, suggesting that the (Z)-diastereoisomer is preferred, which supports the experimentally observed (E/Z)-distribution.
Photoelectron Spectra of Phenylethynes, I. - Phenylethyne - Model Probe for Substituent Effects
Elbel, Susanne,Lienert, Klaus,Krebs, Adolf,Dieck, Heindirk tom
, p. 1785 - 1797 (2007/10/02)
The four low energy ?-orbitals of ethynylbenzene (1) respond differently to substitution at the alkyne site due to their respective symmetry properties.The gas phase He(I) PE spectra of the series 1 - 13 (C6H5-CC-R) are presented and the energetic tren
