It was observed that the halohydroxylation of 1, 2-allenyl sulfides or selenides with Br2 (CuBr2 or NBS) or I2 and water demonstrated a fairly good regioselectivity (ie, the CC bond that is remote from the S or Se atom was halohydroxylated with the halogen atom connecting to the middle carbon atom and the hydroxyl group connecting to the non-S terminal carbon or Se-substituted terminal carbon atom of the allene moiety), leading to ...
