RESUMO
The two novel cyclization modes of ß-CF3-1,3-enynes are presented herein for the divergent construction of F- and CF3-containing N-fused heterocycles. Fluorinated pyrazolo[1,5-a]pyridines were afforded from ß-CF3-1,3-enynes with N-aminopyridiniums ylides via detrifluoromethylative [2 + 3] cyclizations, followed by fluorine transfer from a CF3 unit. Whereas reaction with N-aminoisoquinoliniums ylides gave CF3-substituted pyrrolo[2,1-a]isoquinoline by unprecedented fragmentation [3 + 2]-cycloadditions. Additionally, gram-scale experiments and synthetic utility are demonstrated by further derivatization of fluorinated heterocycles.
RESUMO
OBJECTIVES: This study aimed to investigate corneal epithelial and topographic changes caused by two commercial myopia orthokeratology (ortho-k) designs. METHODS: Twenty-six subjects fitted with vision shape treatment (VST) lenses and 30 subjects fitted with corneal reshaping therapy (CRT) lenses were reviewed 1 day, 1 week, and 1 month after lens initiation. A spectral-domain optical coherence tomography system was used to create epithelial maps that were in turn used to determine the average epithelial thickness of each zone and the diameter of treatment zone. By measuring the topographic tangential differential map, the treatment zone diameter and the power and width of the high convex zone (HCZ) were obtained. All epithelial thicknesses and topographic corneal variations recorded were analyzed. RESULTS: At the central zone, the epithelial thickness changes (â³ET) decreased significantly after 1 day of ortho-k in two groups. At 2- to 9-mm peripheral zone, ortho-k increased â³ET until 1 week in the VST group, whereas it kept increasing in the CRT group after 1 week. At 1 month, the central â³ET is -9.51±2.38 mm in the VST group, which was comparable to -8.72±3.43 mm in the CRT group. The nasal HCZ power and the â³ET of nasal and inferior nasal were significantly larger in the CRT group. A positive correlation was found between the HCZ power and â³ET generated by VST-type lenses inferiorly and temporally. For the CRT group, a positive correlation was found between inferior HCZ power and â³ET. CONCLUSIONS: At the early stage of ortho-k, epithelial thickness and topography change quickly and simultaneously. Epithelial changes were in line with corneal topography reshaping. Epithelial and optical remodelling were affected by different lens types.