Fluorinative Rearrangements of Substituted Phenylallenes Mediated by (Difluoroiodo)toluene: Synthesis of α-(Difluoromethyl)styrenes
作者:Zhensheng Zhao、Léanne Racicot、Graham K. Murphy
DOI:10.1002/anie.201706798
日期:2017.9.11
(difluoroiodo)toluene in the presence of 20 mol % BF3⋅OEt2 to yield α‐difluoromethyl styrenes. This unprecedented reaction was entirely chemoselective for the internal allene π bond, and showed remarkable regioselectivity during the fluorination event. Substituted phenylallenes, phenylallenes possessing both phenyl‐ and α‐allenyl substituents, and diphenylallenes were investigated, and good functional‐group
Catalytic Enantioselective Synthesis of Highly Functionalized Difluoromethylated Cyclopropanes
作者:Maxence Bos、Wei-Sheng Huang、Thomas Poisson、Xavier Pannecoucke、André B. Charette、Philippe Jubault
DOI:10.1002/anie.201707375
日期:2017.10.16
The first catalyticasymmetricsynthesis of highly functionalized difluoromethylated cyclopropanes is described. The method, based on a rhodium‐catalyzed cyclopropanation of difluoromethylated olefins, gives access to a broad range of cyclopropanes bearing ester, ketone, or nitro functional groups. By using Rh2((S)‐BTPCP)4 as a catalyst, the corresponding products were obtained in high yields and high
Synthesis of<i>gem</i>-Difluoroalkenes via β-Fluoride Elimination of Organorhodium(I)
作者:Tomoya Miura、Yoshiteru Ito、Masahiro Murakami
DOI:10.1246/cl.2008.1006
日期:2008.9.5
Treatment of α-(trifluoromethyl)styrenes with arylboronic esters and MeMgCl in the presence of a rhodium(I) catalyst affords gem-difluoroalkenes. The reaction proceeds through the addition of arylrhodium(I) species across the electron-deficient carbon–carbon double bond and the subsequent β-fluoride elimination.
Photocatalytic Hydroacylation of Alkenes by Directly Using Acyl Oximes
作者:Lan Zheng、Peng-Ju Xia、Qing-Lan Zhao、Yu-En Qian、Wen-Nian Jiang、Hao-Yue Xiang、Hua Yang
DOI:10.1021/acs.joc.0c01818
日期:2020.9.18
are directly used as the acyl radical precursors in the hydroacylation reactions for the first time. In this work, acyl radicals can be effectively generated viaβ-scission of a phosphoranyl radical under photocatalytic conditions. As a result, the hydroacylation of alkenes triggered by the resulting acyl radicals leads to facile syntheses of a range of valuable ketones.
Controlled Synthesis of α-CF<sub>2</sub>H or α-CF<sub>2</sub>Cl Styrenes from the Same Precursors: Dehydrazinative Hydrogenation or Chlorination of 3,3-Difluoroallyl Hydrazines
provides for the first time a facile method for the direct and selective synthesis of α-CF2H and α-CF2Cl styrenes starting from the same precursors, which is easy to scale up and displays a broad substrate scope and good functional group tolerance. Moreover, product derivatization experiments demonstrated that the resulting α-CF2Cl styrenes are practical and versatilebuildingblocks for the diversified