Perfluoro-2,3-dialkyloxaziridines

Both thioxanthene and thioxanthone give a ca. 1 1 mixture of sulfoxide and sulfone in high overall conversion in a Ti02-mediated photocatalytic oxidation (Scheme 62) <1998JPH(114)213>. Thioxanthone is oxidized to either its sulfoxide or sulfone in high yields and with excellent selectivity by stoichiometric quantities of perfluoro-rfr-2,3-dialkyloxaziridines 324 at —40 °C (Equation 57) <1994JOC2762>. 

Perfluoro-cfv-2,3-dialkyloxaziridines (64a) also selectively oxidizes sulfides to sulfoxides at — 40°C in CFC13 <94JOC2762>, for example, the hydrochloride of promazine (67), a neuroleptic drug, is oxidized to (68) in 90-94% yield (Equation (14)). At higher temperatures and/or with excess oxidant the corresponding sulfones are rapidly formed even at —20 to 0°C. 

Perfluoro-c -2,3-dialkyloxaziridines (64) are prepared in good yield (68-77%) by MCPBA oxidation of the corresponding perfluoroazaalkenes (188) (Equation (46)) <93JOC4754>. To be successful, the peracid needs to be > 80% pure, well-dried, and the solvent needs to be acetonitrile. Interestingly, oxidation does not proceed in CH2C12. A series of 3-/-butyl-3-( 1 -haloalkyl)oxaziridine were prepared by oxidation of the corresponding a-chloro, a-bromo, a,a-dichloro, and a,a-dibromo aldimines with MCPBA <92T7345>. 

Cavicchioh, M. Montanari, V Resnati, G. Oxyfunctionahzation reactions by perfluoro CM -2,3-dialkyloxaziridines. Enantioselective conversion of silanes into silanols. 

Arnone, A. Novo, B. Pregnolato, M. Resnati, G. Terreni, M. Conversion of thio- and selenophosphoryl into phosphoryl group by perfluoro cw-2,3-dialkyloxaziridines. J. Org. Chem. 1997, 62, 6401. 

Bernard , R. Novo, B. Resnati, G. Reactivity of perfluoro-(cw-2,3-dialkyloxaziridines) with heteroaromatic nitrogen compounds. J. Chem. Soc., Perkin Trans. 1 1996, 2517. 

In 1994, the oxidation of sulfides by perfluoro-cw-2,3-dialkyloxaziridines, was reported by DesMarteau [120]. On using either of the fluorine containing oxaziridines (59 or 60) high yields were obtained of the sulfoxide (90-97%, Scheme 1.53). 

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