Journal
JOURNAL OF FLUORINE CHEMISTRY
Volume 128, Issue 7, Pages 806-812Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.jfluchem.2007.03.009
Keywords
tetrabutylammonium fluoride; amine deprotection; demethylation; nucleophilic substitution; S(N)2; SNAr; arene fluorination; PET; leaving groups; reverse Menschutkin
Categories
Ask authors/readers for more resources
Fluorination of aromatic compounds by nucleophilic displacement of trimethylanilinium salts by fluoride is a commonly used reaction for radiotracer synthesis. Though the liberated trimethylamine is thought to be an excellent leaving group for this type Of SNAr reaction, scattered reports show that amine demethylation (reverse Menschutkin reaction) sometimes dominates over substitution, particularly when relatively electron rich fluoroarenes are the desired targets. Here we provide systematic experimental and theoretical studies of trimethylanilinium demethylation and substitution. Results from these studies highlight the limits of this leaving group in fluoroarene synthesis and have important ramifications for the design of nucleophilic fluorinating agents featuring ammonium cations. (c) 2007 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available