The organoselenium-induced ring-closure reactions of γ-substituted β, γ-unsaturated hydroxamic acids afforded cyclic phenylseleno N-hydroxy imidates or phenylseleno N-hydroxy γ-lactams as the kinetically or thermodynamically controlled products, respectively.
Treatment of the di-2-[(IS)-1-(methylthio)ethyl]phenyl diselenide with bromine and silver triflate afforded the corresponding selenyl triflate which was used in situ as a strongly electrophilic selenium reagent to effect the asymmetric synthesis of oxygen- or nitrogen-containing heterocycles. Cyclic ethers, lactones, lactams or N-protected pyrrolidines have been prepared in good yield with complete regioselectivity and high diastereoselectivity. (C) 2001 Elsevier Science Ltd. All rights reserved.
Tiecco Marcelo, Testaferri Lorenzo, Tingoli Marco, Marini Francesca, J. Chem. Soc. Chem. Commun, (1994) N 2, S 221-222