Chloride ion-catalyzed generation of difluorocarbene for efficient preparation of gem-difluorinated cyclopropenes and cyclopropanes
作者:Fei Wang、Wei Zhang、Jieming Zhu、Huaifeng Li、Kuo-Wei Huang、Jinbo Hu
DOI:10.1039/c0cc04548a
日期:——
A chloride ion-catalyzed generation of difluorocarbene from a relatively non-toxic and inexpensive precursor, Me(3)SiCF(2)Cl (1), under mild and neutral conditions leads to an efficient preparation of gem-difluorocyclopropenes and difluorocyclopropanes through [2 + 1] cycloaddition reactions with alkynes and alkenes, respectively.
Synthesis of gem-Difluorinated Cyclopropanes and Cyclopropenes: Trifluoromethyltrimethylsilane as a Difluorocarbene Source
作者:Fei Wang、Tao Luo、Jinbo Hu、Ying Wang、Hema S. Krishnan、Parag V. Jog、Somesh K. Ganesh、G. K. Surya Prakash、George A. Olah
DOI:10.1002/anie.201101691
日期:2011.7.25
Highly versatile: The Ruppert–Prakash reagent (Me3SiCF3) can be an efficient source of difluorocarbene. By varying the nonmetallic initiator that is used (F− at lower temperatures and I− at higher temperatures), a range of structurally diverse alkenes and alkynes can be converted into the corresponding gem‐difluorinated cyclopropanes and cyclopropenes in good yields (see scheme).
Copper‐Catalyzed Enantioselective Hydrosilylation of
<i>gem</i>
‐Difluorocyclopropenes Leading to a Stereochemical Study of the Silylated
<i>gem</i>
‐Difluorocyclopropanes
作者:Keisuke Sekine、Dai Akaishi、Kakeru Konagaya、Shigekazu Ito
DOI:10.1002/chem.202200657
日期:2022.6.7
was appropriate for the enantioselective hydrosilylation of the strained C=C double bond, and the resultant chiral difluorinated three-membered ring was unambiguously characterized. Subsequent activation of the silyl groups in enantio-enriched gem-difluorocyclopropanes showed substantial reduction of the enantiopurity, indicating cleavage of the distal C-C bond leading to the transient acyclic intermediates