A5010420066- Fluorine in Organic Chemistry
- Inorganic Fluorides and Related Compounds
- Organoboron and organosilicon chemistry
- Asymmetric Synthesis and Catalysis
- Dental materials and restorations
- Anatomy and Medical Technology
- Chemical Synthesis and Analysis
- Endodontics and Root Canal Treatments
- Carbohydrate Chemistry and Synthesis
National University of Singapore
2000-2024
We report a general method for the labeling of both CF3 and CF2 H groups in broad range chemical settings (aryl, oxide, sulfide). The utilizes frustrated Lewis pair mediated selective C-F activation to formally substitute fluorine-19 with fluorine-18 two-step defluorination/radiofluorination process, as such can utilize target compounds starting materials. radiotracer precursors be isolated stable salts prior radiofluorination. delivers good radiochemical yields molar activities (up 35.2±6.5...
Frustrated Lewis pairs (FLP) comprising of B(C6F5)3 (BCF) and 2,4,6-triphenylpyridine (TPPy), P(o-Tol)3 or tetrahydrothiophene (THT) have been shown to mediate selective C-F activation in both geminal chemically equivalent distal sites. In comparison other reported attempts using BCF, these reactions appear surprisingly facile. We investigate this reaction through a combination experimental computational chemistry understand the mechanism initial event origin selectivity that prevents...
The effects of aging on the repair bond strengths resin‐modified glass–ionomer cements after different methods surface conditioning were studied. Surface included following: maleic acid; acid with resin application; polyacrylic application. Shear testing between aged and new material was carried out an Instron Universal machine. application gave highest at 3 6 months. There was, however, no statistically significant difference in treatment groups both months storage. Intergroup comparisons...
The silyl reagents Me3SiCF3 (Ruppert–Prakash reagent) and Me3SiCF2H are commonly activated via desilylation to install CF3 CF2H groups. We explore the C–F activation of these using phosphine pyridine Lewis bases in combination with boron and/or silicon based acids give products form [Me3SiCFR(LB)][NTf2] or [HCFR(LB)][NTf2] (R = F H; LB P(o-Tol)3, PPh3, PPh2(C6F5), 2,4,6-Ph3-NC5H2). reaction mechanism is investigated, we find that it likely decomposes Me3SiF difluorocarbene, latter which...
Abstract We report a general method for the labeling of both CF 3 and 2 H groups in broad range chemical settings (aryl, oxide, sulfide). The utilizes frustrated Lewis pair mediated selective C−F activation to formally substitute fluorine‐19 with fluorine‐18 two‐step defluorination/radiofluorination process, as such can utilize target compounds starting materials. radiotracer precursors be isolated stable salts prior radiofluorination. delivers good radiochemical yields molar activities (up...