Reactions involving fluoride ion. Part IX. Syntheses involving octafluoroisobutene
作者:Stephen L. Bell、Richard D. Chambers、Michael Y. Gribble、Jerzy R. Maslakiewicz
DOI:10.1039/p19730001716
日期:——
Octafluoroisobutene reacts with pentafluoropyridine in the presence of fluorideion, at 80°, to give perfluoro-2,4,6-tri-t-butylpyridine whereas, at 20°, perfluoro-4-t-butylpyridine is formed. Reaction of Octafluoroisobutene with tetrafluoropyridazine, at 80°, gives perfluoro-3,6-di-t-butylpyridazine exclusively, although at lower temperatures perfluoro-4-t-butyl or-3,5-t-butyl derivatives are obtained
Fluorination Triggers Fluoroalkylation: Nucleophilic Perfluoro‐
<i>tert</i>
‐butylation with 1,1‐Dibromo‐2,2‐bis(trifluoromethyl)ethylene (DBBF) and CsF
作者:Qian Wang、Quan Tao、Hui Dong、Chuanfa Ni、Xiaoming Xie、Jinbo Hu
DOI:10.1002/anie.202113727
日期:2021.12.20
AbstractPerfluoro‐tert‐butylation reaction has long remained a challenging task. We now report the use of 1,1‐dibromo‐2,2‐bis(trifluoromethyl)ethylene (DBBF) as a practical reagent for perfluoro‐tert‐butylation reactions for the first time. Through a consecutive triple‐fluorination process with DBBF and CsF, the (CF3)3C− species can be liberated and observed, which is able to serve as a robust nucleophilic perfluoro‐tert‐butylating agent for various electrophiles. The power of this synthetic protocol is evidenced by the efficient synthesis of structurally diverse perfluoro‐tert‐butylated molecules. Multiple applications demonstrate the practicability of this method, as well as the superiority of perfluoro‐tert‐butylated compounds as sensitive probes. The perfluoro‐tert‐butylated product was successfully applied in 1H‐ and 19F‐magnetic resonance imaging (MRI) experiment with an ultra‐low field (ULF) MRI system.