P. Milliet

Transfert d'oxygene sur la double liaison ethylenique a partir d'un sel d'oxaziridinium

Abstract Some examples of transfer of oxygen from on oxaziridinium salt to ethylenic derivatives to give epoxides are described.

Peracid oxidation of an immonium fluoroborate a new example of oxaziridinium salt.

Abstract The second oxaziridinium salt described so far has been prepared by alkylation of an oxaziridine and by oxygenation of an immonium salt. This confirms that this function is indeed accessible, though very reactive.

Studies on the reaction of primary and secondary amines with phenylseleninic anhydride and with phenylseleninic acid

Abstract The dehydrogenation under mild conditions of indolines with phenylseleninic anhydride or acid affords good yields of indoles or of 3-phenylselenenyl indoles. Tetrahydroquinoline and -isoquinoline show comparable behaviour. The dehydrogenation of primary amines gives more complicated mixtures from which nitriles and bis-2-phenylselenenylaldehydes can be isolated.

Action de l'acide paranitroperbenzoique sur le tetrafluoroborate de n-methyl-3,4-dihydroisoquinolinium. Formation d'un sel d'oxaziridinium.

Resume Peracidic oxygenation of an iminium salt 4 derived from N-methyl-tetrahydro-1,2,3,4-isoquinolin- leads to an oxaziridinium salt 3 in the presence of a substoichiometric amount of sodium hydrogen carbonate. In stoichiometric amounts of base, the oxaziridinium salt 3 gives a mixture of N-methyl-isoquinolinium 5 , the opened structure 6 , and starting material 4 . 6 .

La transformation d'indolines en indoles et d'autres reactions apparentees

Abstract Phenylseleninic anhydride reacts rapidly with indolines at 0° to give, when the β-position is substituted, the corresponding indoles. When the β-position is unsubstituted β-phenylseleno- indoles are formed. These are readily reduced by nickel boride to the parent indole. Tetrahyrdroisoquinoline is dehydrogenated with comparable ease. Phenylseleninic acid is also an efficient agent for these dehydrogenations.

Acid catalyzed oxygen transfer from an oxaziridine to a thioether

Abstract Oxygen can be transferred from the oxaziridine derived from 3,4-dihydroisoquinoline to a thio-ether. As shown by the different pathways followed on various conditions, the oxygen transfer depends on acid catalysis and on the nucleophilicity and basicity of the substrate.

An improved procedure for the conversion of indolines into indoles

Abstract The addition of a sacrificial enamine (such as indole), or of a vinyl ether (like dihydropyran) to an indoline during dehydrogenation by phenylseleninic anhydride dramatically improves the yield of the corresponding indole. This is due to scavenging of Se 11 phenylselenenating species.

Dehydrogenation with phenylseleninic anhydride in the total synthesis of ergot alkaloids

The standardised procedure for dehydrogenation of indolines into indoles with phenylseleninic anhydride 1 was successfully applied to the final steps in the total synthesis of ergot alkaloids.

Action des sulfonyloxaziridines sur une imine. Obtention d'une nitrone par transfert regioselectif de l'oxygene sur l'azote

Abstract A pyrrolinic imine has been found to react concurrently with the nitrogen or the oxygen of a N -sulfonyl oxaziridine leading to a N-sulfonyl diaziridine and a nitrone respectively. By contrast an oxaziridine is obtained with a peracid. A possible relation between the regioselectivity of the oxygen transfer and the nature of the reagent is outlined.

Dehydrogenation with benzeneseleninic anhydride in the total synthesis of ergot alkaloids

Investigation of the dehydrogenative conversion of indolines into indoles with benzeneseleninic anhydride (1) resulted in the development of an efficient standardised procedure, which was successfully applied to the final steps in first total synthesis of (±)-lysergol (18), (±)-isolysergol (27), and (±)-elymoclavine (29).