69009-72-9Relevant academic research and scientific papers
Chiral fluoro ketones for catalytic asymmetric epoxidation of alkenes with oxone
Denmark, Scott E.,Matsuhashi, Hayao
, p. 3479 - 3486 (2002)
Two structurally dissimilar, chiral fluoro ketones have been prepared and their potential as enantioselective catalysts for asymmetric epoxidation with Oxone has been evaluated. The tropinone-based ketone (-)-5 was easily prepared and showed excellent reactivity but only modest enantioselectivity. The biphenyl-based ketone (-)-6 was prepared in a somewhat lengthy synthesis (along with its monofluoro and geminal fluoro analogues). This ketone exhibited only modest reactivity; 30 mol % of (-)-6 was needed to bring about complete conversion in a reasonable time. The enantioselectivity of this catalyst was generally much higher, but again very substrate dependent.
Preparative Optical Resolution of Axial- and Planar-chiral Benzene Derivatives, Metallocenes, and Methanoazaannulenes by Medium Pressure Chromatography on Triacetylcellulose
Schloegl, Karl,Widhalm, Michael
, p. 3042 - 3048 (2007/10/02)
Medium pressure chromatography (at 4 - 6 bar and 6 - 40 deg C) on specially prepared triacetylcellulose in ethanol (or ether) renders possible an efficient preparative optical resolution of chiral benzene derivatives, (benzene)tricarbonylchromium complexes (benchrotrenes), ferrocenes, and azaannulenes.The method is presented for 15 selected examples such as 1,3-diferrocenyl-1,3-diphenylallene (1), 2,2'-spirobiindanes (2,3), biphenyl derivatives (4 - 8) and their tricarbonylchromium complexes (9 - 11), metacyclophanes (12 - 14) and 2,7-methanoazaannulenes (15,16) as well as for Troeger's base.In ten cases a quantitative separation of the enantiomers and in two an appr. 80 percent enantiomeric enrichment was achieved whereas for three compounds only a partial resolution took place.
