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).
Borane-Catalyzed C–F Bond Functionalization of <i>gem</i>-Difluorocyclopropenes Enables the Synthesis of Orphaned Cyclopropanes
作者:Joseph P. Mancinelli、Wang-Yeuk Kong、Wentao Guo、Dean J. Tantillo、Sidney M. Wilkerson-Hill
DOI:10.1021/jacs.3c05278
日期:2023.8.9
steric and electronic properties and enables access to 3,3-bis(difluoromethyl)cyclopropenes in short order. The resulting cyclopropene products are readily reduced to the corresponding orphaned cyclopropanes under hydrogenation conditions. Quantum chemical calculations reveal the nature of the C–F bond cleavage steps and provide evidence for catalysis by boron and not silylated oxonium ions, though
Synthesis of<i>gem</i>-Difluorocyclopropa(e)nes and O<i>-</i>, S<i>-</i>, N<i>-</i>, and P-Difluoromethylated Compounds with TMSCF<sub>2</sub>Br
作者:Lingchun Li、Fei Wang、Chuanfa Ni、Jinbo Hu
DOI:10.1002/anie.201306703
日期:2013.11.18
Two-in-one: Me3 SiCF2 Br is an efficient difluorocarbene source and is compatible with both neutral and aqueous basic conditions. Bromide-ion-initiated [2+1] cycloaddition with alkenes/alkynes and hydroxide ion promoted α-addition with (thio)phenols, (thio)alcohols, sulfinates, heterocyclic amines, and H-phosphine oxides give the corresponding gem-difluorinated compounds with broad functional-group tolerance.
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.
Palladium Hydride-Enabled Hydroalkenylation of Strained Molecules
作者:Ziyan Zhang、Vladimir Gevorgyan
DOI:10.1021/jacs.2c09045
日期:2022.11.16
palladium hydride enabled hydroalkenylation of strained molecules. This new mild protocol proceeds via a regio- and chemoselective hydropalladation step, followed by a photoinduced radical alkyl Heck reaction. This methodology represents a new reactivity mode for strained molecules and opens new avenues for photoinduced palladium catalysis. The reaction is compatible with a wide range of functional groups