Structural and Kinetic Considerations for the Application of the Traceless Staudinger Ligation to Future 18F Radiolabeling Using XRD and 19F NMR. Issue 1 (23rd November 2017)

• Record Type: Journal Article
• Authors: Köckerling, Martin; Mamat, Constantin
• Is Part Of: International journal of chemical kinetics. Volume 50:Issue 1(2018)
• Page Start: 31
• Page End: 40
• Publication Date: 2017-11-23
• Subjects: Chemical kinetics -- Periodicals; 541.394
• DOI: 10.1002/kin.21137
• Languages: English
• ISSNs: 0538-8066

Abstract

ABSTRACT: A 4‐fluorobenzoate‐functionalized phosphane was synthesized and reacted with different azides using the traceless Staudinger ligation as a representative sample reaction for future radiolabeling purposes with short‐lived radionuclides like fluorine‐18. For this purpose, the reaction rate was evaluated at different temperatures. The effect of starting material concentrations and the influence of the steric effect coming from the applied azides were investigated. 19 F NMR was used to determine the reaction half‐live (τ1/2 ) and the reaction rate constant ( k obs ) of this ligation under mild reaction conditions in a water–acetonitrile mixture. Furthermore, the phosphane key compound1 (orthorhombic, space group Pna 21, a = 18.6363(9), b = 8.3589(4), c = 18.5480(9) Å, V = 2889.4(2) Å 3, Z = 8, Dobs = 1.277 g/cm 3 ), which acts as starting material for all subsequent syntheses, and the fluorine‐containing phosphane3 (monoclinic, space group P 21 / c, a = 8.321(2), b = 16.160(4), c = 14.940(4) Å, β = 99.51(1)°, V = 1981.4(8) Å 3, Z = 4, Dobs = 1.342 g/cm 3 ) were analyzed by single‐crystal XRD.