Chemistry Letters, Vol.35, No.6, 626-627, 2006
Synthesis of 1,3-selenazines and 1,3-selenazolidines via intramolecular addition of N-allylselenoureas
The regiochemistry of intramolecular addition of N-allyl-selenoureas leading to 2-imino-5-methyl-1,3-selenazolidines or 2-amino-5-iodo-4H-5,6-dihydro-1,3-selenazines depends on the treatment of hydrogen chloride or iodine: treatment of hydrogen chloride with N-allylselenoureas affords preferentially 2-imino-5-methyl-1,3-selenazolidines through 5-endo closure, whereas treatment of iodine affords preferentially 2-amino-5-iodo-4H-5,6-dihydro-1,3-selenazines through 6-exo closure.