10.1021/om7012293
The research focuses on the synthesis, characterization, and catalytic application of tetrabenzo[a,c,g,i]fluorenyltitanium(III) and -(IV) complexes. The study involves reacting tetrabenzo[a,c,g,i]fluorenyllithium with TiCl3 to form TbfTiCl2(THF), which is then converted to TbfTiCl3 through oxidative chlorination. Further reactions with lithium phenoxides yield a series of titanium complexes, TbfTiCl2(OAr). The complexes are characterized using IR, MS, NMR measurements, and X-ray crystallography. Additionally, the article describes the synthesis of titanium complexes with TEMPO and OtBu radicals. Ethylene polymerization experiments are conducted using d-MAO as a catalyst, with the activities of the compounds reported in terms of polymer production rates and molecular weights. The reactants used include various lithium phenoxides, TEMPO, and di-tert-butylperoxide, while analyses involve melting point determination, mass spectrometry, infrared spectroscopy, and elemental analysis.
10.1016/j.tetlet.2007.12.128
The research focuses on the radical [18F]fluoroarylation of various olefins using 4-[18F]fluorobenzenediazonium ions, offering a novel approach to synthesize radiopharmaceuticals containing a deactivated, 4-[18F]fluoro substituted phenyl group. The study demonstrates the methodology's suitability for the synthesis of 18F-labeled stilbenes, with stilbene 7 being synthesized within 80 minutes with a 30–45% overall radiochemical yield starting from [18F]fluoride. The experiments involved reacting 4-fluorobenzenediazonium tetrafluoroborate with substrates such as arecoline, ecgonidine methylate, and styrenes under optimized conditions using titanium(III)-chloride in dilute hydrochloric acid as a reductant. The analyses included determining radiochemical yields through reverse-phase high-performance liquid chromatography (RP-HPLC) with gradient elution and UV detection at 214 nm, as well as assessing diastereoselectivity in the synthesized products.