Transition Metal‐free
<i>gem</i>
‐difluorocyclopropanation of Alkenes with CF
<sub>3</sub>
SiMe
<sub>3</sub>
−NaI System: a Recipe for Electron‐deficient Substrates
作者:Pavel S. Nosik、Sergey V. Ryabukhin、Oleksandr O. Grygorenko、Dmitriy M. Volochnyuk
DOI:10.1002/adsc.201801006
日期:2018.11.5
Reaction of various electron‐deficientalkenes, as well as functionalized styrene derivatives with CF3SiMe3−NaI system is studied. Relative reactivity of the substrates is established. It is shown that many α,β‐unsaturated esters can be difluorocyclopropanated efficiently under “slow addition protocol” conditions, which provides access to mono‐ and spirocyclic gem‐difluorocyclopropyl‐substituted carboxylic
The title compounds were hydrogenolyzd over PdO or Raney nickel. The C2–C3 bond of the cyclopropane ring underwent cleavage exclusively over the both catalysts. The contribution of the fluorine substituent to the lengthening and weakening the C2–C3 bond of the cyclopropane ring seems to become a dominant factor in the regioselectivity.
organic synthesis due to their high reactivity. Herein, we report a Lewis acid-catalyzed cross-coupling reaction of mono- and disubstituted gem-difluorinated cyclopropanes with nucleophiles. The formation of a fluoroallyl cation species triggered via the Lewisacid-assisted activation of the C–F bond is proposed in this transformation. The cation species is then trapped by the nucleophiles, including
Synthesis of Chiral Hypervalent Trifluoromethyl Organobismuth Complexes and Enantioselective Olefin Difluorocarbenation Screenings
作者:Thomas Louis‐Goff、Huu Vinh Trinh、Eileen Chen、Arnold L. Rheingold、Jakub Hyvl
DOI:10.1002/cplu.202200450
日期:2023.2
Progress towardenantioselective difluorocyclopropanation: This work presents synthesis and characterization of chiral hypervalent trifluoromethyl organobismuthanes. One complex was synthesized as a single stereoisomer and was screened in catalytic olefin difluorocarbenation with prochiral olefins and TMS-CF3, as a terminal source of CF2. The screened catalyst showed a good catalytic activity; however