The Reactions of Alkenes with Phenyl- N -triflylimino-λ 3 -iodane: Solvent and Oxidant Impact.

The reactions of alkenes with phenyl- N -triflylimino-λ 3 -iodane PhI=NTf ( 1 ) have been studied in different conditions. In methylene chloride, in the presence of N -halosuccinimides, the products of mono and bis-triflamidation were obtained. In MeCN, the product of bromotriflamidation (with NBS) with solvent interception or of bis-triflamidation (with NIS) is formed. The reaction with trans -stilbene in acetonitrile with NBS gave rise to cyclization to 2-methyl-4,5-diphenyl-1-triflyl-4,5-dihydro-1 H -imidazole. In contrast, with NIS as an oxidant, both in CH 2 Cl 2 and MeCN, the major product was 2,3-diphenyl-1-triflylaziridine formed in good yield. With NBS, aziridine is also formed but as a minor product, the major one being a mixture of diastereomers of the product of bromotriflamidation. The reaction of compound 1 with vinylcyclohexane in methylene chloride affords the mixtures of regioisomers of the products of halotriflamidation, whereas in acetonitrile, the products of solvent interception and cyclization to the imidazoline are formed. A mechanism explaining the formation of all isolated products is proposed.