Journal Article

FZJ-2019-03786

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Baeyer-Villiger oxidation tuned to chemoselective conversion of non-activated [18F]fluorobenzaldehydes to [18F]fluorophenols

Ermert, J. (Corresponding author)FZJ* ; Meleán, J. C.FZJ* ; Humpert, S.FZJ* ; Modemann, D.FZJ* ; Krupp, D. ; Kern, I. ; Kreft, S. ; Coenen, H. H.FZJ*

2019
Wiley New York, NY [u.a.]

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Please use a persistent id in citations: doi:10.1002/jlcr.3740

Abstract: A reaction pathway via oxidation of [18F]fluorobenzaldehydes offers a very useful tool for the no‐carrier‐added radiosynthesis of [18F]fluorophenols, a structural motive of several potential radiopharmaceuticals. A considerably improved chemoselectivity of the Baeyer‐Villiger oxidation (BVO) towards phenols was achieved, employing 2,2,2‐trifluoroethanol as reaction solvent in combination with Oxone or m‐CPBA as oxidation agent. The studies showed the necessity of H2SO4 addition, which appears to have a dual effect, acting as catalyst and desiccant. For example, 2‐[18F]fluorophenol was obtained with a RCY of 97% under optimised conditions of 80°C and 30‐minute reaction time. The changed performance of the BVO, which is in agreement with known reaction mechanisms via Criegee intermediates, provided the best results with regard to radiochemical yield (RCY) and chemoselectivity, i.e. formation of [18F]fluorophenols rather than [18F]fluorobenzoic acids. Thus, after a long history of the BVO, the new modification now allows an almost specific formation of phenols, even from electron‐deficient benzaldehydes. Further, the applicability of the tuned, chemoselective BVO to the n.c.a. level and to more complex compounds was demonstrated for the products n.c.a. 4‐[18F]fluorophenol (RCY 95%; relating to 4‐[18F]fluorobenzaldehyde) and 4‐[18F]fluoro‐m‐tyramine (RCY 32%; relating to [18F]fluoride), respectively.

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Contributing Institute(s):

1. Nuklearchemie (INM-5)

Research Program(s):

1. 573 - Neuroimaging (POF3-573) (POF3-573)

Appears in the scientific report 2019

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Database coverage:
; BIOSIS Previews ; Clarivate Analytics Master Journal List ; Current Contents - Life Sciences ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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