Small organophosphorus-selenium heterocycles from the selenation of conjugated ketones and enals

Article abstract of DOI:10.1055/s-0031-1290349

Reaction of 2,4-bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide [Woollins' reagent, WR] with equimolar amount of ,-unsaturated ketones [R ¹C(O)C=CR² (R¹ = aryl or alkyl; R² = -aryl)] leads to a series of novel five-membered C₃P(Se)Se hetero-cycles 1-8 in 48-95% isolated yields. Furthermore, WR reacts with one equivalent of aromatic conjugated enals [RC=CC=O, R = Ph and 2-MeOC ₆H₄] to give five-membered C₃P(Se)Se heterocycles 9 and 10 via the cleavage/cyclic extension of WR molecular ring. All new compounds have been characterised spectroscopically (³¹P NMR, ⁷⁷Se NMR, ¹H NMR, ¹³C NMR, IR and mass spectroscopy) and one representative X-ray structure is reported. Georg Thieme Verlag Stuttgart · New York.